Hydroxyalkylated high performance curable polymers

ABSTRACT

Disclosed is a composition which comprises (a) a polymer containing at least some monomer repeat units with photosensitivity-imparting substituents which enable crosslinking or chain extension of the polymer upon exposure to actinic radiation, said polymer being of the formula                    
     wherein x is an integer of 0 or 1, A is one of several specified groups, such as                    
     B is one of several specified groups, such as                    
     or mixtures thereof, and n is an integer representing the number of repeating monomer units, wherein said photosensitivity-imparting substituents are hydroxyalkyl groups; (b) at least one member selected from the group consisting of photoinitiators and sensitizers; and (c) an optional solvent. Also disclosed are processes for preparing the above polymers and methods of preparing thermal ink jet printheads containing the above polymers.

This application is a divisional of application Ser. No. 08/705,365,filed Aug. 29, 1996 now U.S. Pat. No. 5,849,809.

BACKGROUND OF THE INVENTION

The present invention is directed to curable polymers and tophotoresists and thermal ink jet printheads containing these polymers.More specifically, the present invention is directed to high performancepolymers substituted with hydroxyalkyl groups. One embodiment of thepresent invention is directed to a composition which comprises (a) apolymer containing at least some monomer repeat units withphotosensitivity-imparting substituents which enable crosslinking orchain extension of the polymer upon exposure to actinic radiation, saidpolymer being of the formula

wherein x is an integer of 0 or 1, A is

or mixtures thereof, B is

wherein v is an integer of from 1 to about 20,

wherein z is an integer of from 2 to about 20,

wherein u is an integer of from 1 to about 20,

wherein w is an integer of from 1 to about 20.

or mixtures thereof, and n is an integer representing the number ofrepeating monomer units, wherein said photosensitivity-impartingsubstituents are hydroxyalkyl groups; (b) at least one member selectedfrom the group consisting of photoinitiators and sensitizers; and (c) anoptional solvent. Another embodiment of the present invention isdirected to a process which comprises the steps of:

(a) depositing a layer comprising a polymer of the above formula onto alower substrate in which one surface thereof has an array of heatingelements and addressing electrodes having terminal ends formed thereon,said polymer being deposited onto the surface having the heatingelements and addressing electrodes thereon;

(b) exposing the layer to actinic radiation in an imagewise pattern suchthat the polymer in exposed areas becomes crosslinked or chain extendedand the polymer in unexposed areas does not become crosslinked or chainextended, wherein the unexposed areas correspond to areas of the lowersubstrate having thereon the heating elements and the terminal ends ofthe addressing electrodes;

(c) removing the polymer in the unexposed areas, thereby formingrecesses in the layer, said recesses exposing the heating elements andthe terminal ends of the addressing electrodes;

(d) providing an upper substrate with a set of parallel grooves forsubsequent use as ink channels and a recess for subsequent use as amanifold, the grooves being open at one end for serving as dropletemitting nozzles; and

(e) aligning, mating, and bonding the upper and lower substratestogether to form a printhead with the grooves in the upper substratebeing aligned with the heating elements in the lower substrate to formdroplet emitting nozzles, thereby forming a thermal ink jet printhead.Yet other embodiments of the present invention are directed to methodsfor preparing polymers of the above formula. Still other embodiments ofthe present invention are directed to crosslinked or chain extendedpolymers of the above formula, wherein the crosslinking or chainextension occurs through bisazide groups or urethane groups.

In microelectronics applications, there is a great need for lowdielectric constant, high glass transition temperature, thermallystable, photopatternable polymers for use as interlayer dielectriclayers and as passivation layers which protect microelectroniccircuitry. Poly(imides) are widely used to satisfy these needs; thesematerials, however, have disadvantageous characteristics such asrelatively high water sorption and hydrolytic instability. There is thusa need for high performance polymers which can be effectivelyphotopatterned and developed at high resolution.

One particular application for such materials is the fabrication of inkjet printheads. Ink jet printing systems generally are of two types:continuous stream and drop-on-demand. In continuous stream ink jetsystems, ink is emitted in a continuous stream under pressure through atleast one orifice or nozzle. The stream is perturbed, causing it tobreak up into droplets at a fixed distance from the orifice. At thebreak-up point, the droplets are charged in accordance with digital datasignals and passed through an electrostatic field which adjusts thetrajectory of each droplet in order to direct it to a gutter forrecirculation or a specific location on a recording medium. Indrop-on-demand systems, a droplet is expelled from an orifice directlyto a position on a recording medium in accordance with digital datasignals. A droplet is not formed or expelled unless it is to be placedon the recording medium.

Since drop-on-demand systems require no ink recovery, charging, ordeflection, the system is much simpler than the continuous stream type.There are different types of drop-on-demand ink jet systems. One type ofdrop-on-demand system has as its major components an ink filled channelor passageway having a nozzle on one end and a piezoelectric transducernear the other end to produce pressure pulses. The relatively large sizeof the transducer prevents close spacing of the nozzles, and physicallimitations of the transducer result in low ink drop velocity. Low dropvelocity seriously diminishes tolerances for drop velocity variation anddirectionality, thus impacting the system's ability to produce highquality copies. Drop-on-demand systems which use piezoelectric devicesto expel the droplets also suffer the disadvantage of a slow printingspeed.

The other type of drop-on-demand system is known as thermal ink jet, orbubble jet, and produces high velocity droplets and allows very closespacing of nozzles. The major components of this type of drop-on-demandsystem are an ink filled channel having a nozzle on one end and a heatgenerating resistor near the nozzle. Printing signals representingdigital information originate an electric current pulse in a resistivelayer within each ink passageway near the orifice or nozzle, causing theink in the immediate vicinity to vaporize almost instantaneously andcreate a bubble. The ink at the orifice is forced out as a propelleddroplet as the bubble expands. When the hydrodynamic motion of the inkstops, the process is ready to start all over again. With theintroduction of a droplet ejection system based upon thermally generatedbubbles, commonly referred to as the “bubble jet” system, thedrop-on-demand ink jet printers provide simpler, lower cost devices thantheir continuous stream counterparts, and yet have substantially thesame high speed printing capability.

The operating sequence of the bubble jet system begins with a currentpulse through the resistive layer in the ink filled channel, theresistive layer being in close proximity to the orifice or nozzle forthat channel. Heat is transferred from the resistor to the ink. The inkbecomes superheated far above its normal boiling point, and for waterbased ink, finally reaches the critical temperature for bubble formationor nucleation of around 280° C. Once nucleated, the bubble or watervapor thermally isolates the ink from the heater and no further heat canbe applied to the ink. This bubble expands until all the heat stored inthe ink in excess of the normal boiling point diffuses away or is usedto convert liquid to vapor, which removes heat due to heat ofvaporization. The expansion of the bubble forces a droplet of ink out ofthe nozzle, and once the excess heat is removed, the bubble collapses.At this point, the resistor is no longer being heated because thecurrent pulse has passed and, concurrently with the bubble collapse, thedroplet is propelled at a high rate of speed in a direction towards arecording medium. The surface of the printhead encounters a severecavitational force by the collapse of the bubble, which tends to erodeit. Subsequently, the ink channel refills by capillary action. Thisentire bubble formation and collapse sequence occurs in about 10microseconds. The channel can be refired after 100 to 500 microsecondsminimum dwell time to enable the channel to be refilled and to enablethe dynamic refilling factors to become somewhat dampened. Thermal inkjet equipment and processes are well known and are described in, forexample, U.S. Pat. Nos. 4,601,777, 4,251,824, 4,410,899, 4,412,224,4,532,530, and 4,774,530, the disclosures of each of which are totallyincorporated herein by reference.

The present invention is suitable for ink jet printing processes,including drop-on-demand systems such as thermal ink jet printing,piezoelectric drop-on-demand printing, and the like.

In ink jet printing, a printhead is usually provided having one or moreink-filled channels communicating with an ink supply chamber at one endand having an opening at the opposite end, referred to as a nozzle.These printheads form images on a recording medium such as paper byexpelling droplets of ink from the nozzles onto the recording medium.The ink forms a meniscus at each nozzle prior to being expelled in theform of a droplet. After a droplet is expelled, additional ink surges tothe nozzle to reform the meniscus.

In thermal ink jet printing, a thermal energy generator, usually aresistor, is located in the channels near the nozzles a predetermineddistance therefrom. The resistors are individually addressed with acurrent pulse to momentarily vaporize the ink and form a bubble whichexpels an ink droplet. As the bubble grows, the ink bulges from thenozzle and is contained by the surface tension of the ink as a meniscus.The rapidly expanding vapor bubble pushes the column of ink filling thechannel towards the nozzle. At the end of the current pulse the heaterrapidly cools and the vapor bubble begins to collapse. However, becauseof inertia, most of the column of ink that received an impulse from theexploding bubble continues its forward motion and is ejected from thenozzle as an ink drop. As the bubble begins to collapse, the ink stillin the channel between the nozzle and bubble starts to move towards thecollapsing bubble, causing a volumetric contraction of the ink at thenozzle and resulting in the separation of the bulging ink as a droplet.The acceleration of the ink out of the nozzle while the bubble isgrowing provides the momentum and velocity of the droplet in asubstantially straight line direction towards a recording medium, suchas paper.

Ink jet printheads include an array of nozzles and may, for example, beformed of silicon wafers using orientation dependent etching (ODE)techniques. The use of silicon wafers is advantageous because ODEtechniques can form structures, such as nozzles, on silicon wafers in ahighly precise manner. Moreover, these structures can be fabricatedefficiently at low cost. The resulting nozzles are generally triangularin cross-section. Thermal ink jet printheads made by using theabove-mentioned ODE techniques typically comprise a channel plate whichcontains a plurality of nozzle-defining channels located on a lowersurface thereof bonded to a heater plate having a plurality of resistiveheater elements formed on an upper surface thereof and arranged so thata heater element is located in each channel. The upper surface of theheater plate typically includes an insulative layer which is patternedto form recesses exposing the individual heating elements. Thisinsulative layer is referred to as a “pit layer” and is sandwichedbetween the channel plate and heater plate. For examples of printheadsemploying this construction, see U.S. Pat. Nos. 4,774,530 and 4,829,324,the disclosures of each of which are totally incorporated herein byreference. Additional examples of thermal ink jet printheads aredisclosed in, for example, U.S. Pat. Nos. 4,835,553, 5,057,853, and4,678,529, the disclosures of each of which are totally incorporatedherein by reference.

The photopatternable polymers prepared by the process of the presentinvention are also suitable for other photoresist applications,including other microelectronics applications, printed circuit boards,lithographic printing processes, interlayer dielectrics, and the like.

U.S. Pat. No. 3,914,194 (Smith), the disclosure of which is totallyincorporated herein by reference, discloses a formaldehyde copolymerresin having dependent unsaturated groups with the repeating unit

wherein R is an aliphatic acyl group derived from saturated acids having2 to 6 carbons, olefinically unsaturated acids having 3 to 20 carbons,or an omega-carboxy-aliphatic acyl group derived from olefinicallyunsaturated dicarboxylic acids having 4 to 12 carbons or mixturesthereof, R₁ is independently hydrogen, an alkyl group of 1 to 10 carbonatoms, or halogen, Z is selected from oxygen, sulfur, the grouprepresented by Z taken with the dotted line represents dibenzofuran anddibenzothiophene moieties, or mixtures thereof, n is a whole numbersufficient to give a weight average molecular weight greater than about500, m is 0 to 2, p and q have an average value of 0 to 1 with theproviso that the total number of p and q groups are sufficient to givegreater than one unsaturated group per resin molecule. These resins areuseful to prepare coatings on various substrates or for pottingelectrical components by mixing with reactive diluents and curing agentsand curing.

“Chloromethylation of Condensation Polymers Containing anoxy-1,4-phenylene Backbone,” W. H. Daly et al., Polymer Preprints, Vol.20, No. 1, 835 (1979), the disclosure of which is totally incorporatedherein by reference, discloses the chloromethylation of polymerscontaining oxy-phenylene repeat units to produce film forming resinswith high chemical reactivity. The utility of 1,4-bis(chloromethoxy)butane and 1-chloromethoxy-4-chlorobutane as chloromethylating agentsare also described.

European Patent Application EP-0,698,823-A1 (Fahey et al.), thedisclosure of which is totally incorporated herein by reference,discloses a copolymer of benzophenone and bisphenol A which was shown tohave deep ultraviolet absorption properties. The copolymer was founduseful as an antireflective coating in microlithography applications.Incorporating anthracene into the copolymer backbone enhanced absorptionat 248 nm. The encapper used for the copolymer varied depending on theneeds of the user and was selectable to promote adhesion, stability, andabsorption of different wavelengths.

M. Camps, M. Chatzopoulos, and J. Montheard, “Chloromethyl Styrene:Synthesis, Polymerization, Transformations, Applications,” JMS—Rev.Macromol. Chem. Phys., C22(3), 343-407 (1982-3), the disclosure of whichis totally incorporated herein by reference, discloses processes for thepreparation of chloromethyl-substituted polystyrenes, as well asapplications thereof.

Y. Tabata, S. Tagawa, and M. Washio, “Pulse Radiolysis Studies on theMechanism of the High Sensitivity of Chloromethylated Polystyrene as anElectron Negative Resist,” Lithography, 25(1), 287 (1984), thedisclosure of which is totally incorporated herein by reference,discloses the use of chloromethylated polystyrene in resistapplications.

M. J. Jurek, A. E. Novembre, I. P. Heyward, R. Gooden, and E.Reichmanis, “Deep UV Photochemistry of Copolymers ofTrimethyl-Silylmethyl Methacrylate and Chloromethylstyrene,” PolymerPreprints, 29(1) (1988), the disclosure of which is totally incorporatedherein by reference, discloses the use of an organosilicon polymer ofchloromethylstyrene for resist applications.

P. M. Hergenrother, B. J. Jensen, and S. J. Havens, “Poly(aryleneethers),” Polymer, 29, 358 (1988), the disclosure of which is totallyincorporated herein by reference, discloses several arylene etherhomopolymers and copolymers prepared by the nucleophilic displacement ofaromatic dihalides with aromatic potassium bisphenates. Polymer glasstransition temperatures ranged from 114 to 310° C. and some weresemicrystalline. Two ethynyl-terminated polyarylene ethers) weresynthesized by reacting hydroxy-terminated oligomers with4-ethynylbenzoyl chloride. Heat induced reaction of the acetylenicgroups provided materials with good solvent resistance. The chemistry,physical, and mechanical properties of the polymers are also disclosed.

S. J. Havens, “Ethynyl-Terminated Polyarylates: Synthesis andCharacterization,” Journal of Polymer Science: Polymer ChemistryEdition, vol. 22, 3011-3025 (1984), the disclosure of which is totallyincorporated herein by reference, discloses hydroxy-terminatedpolyarylates with number average molecular weights of about 2500, 5000,7500, and 10,000 which were synthesized and converted to corresponding4-ethynylbenzoyloxy-terminated polyarylates by reaction with4-ethynylbenzoyl chloride. The terminal ethynyl groups were thermallyreacted to provide chain extension and crosslinking. The cured polymerexhibited higher glass transition temperatures and better solventresistance than a high molecular weight linear polyarylate. Solventresistance was further improved by curing2,2-bis(4-ethynylbenzoyloxy-4′-phenyl)propane, a coreactant, with theethynyl-terminated polymer at concentrations of about 10 percent byweight.

N. H. Hendricks and K. S. Y. Lau, “Flare, a Low Dielectric Constant,High Tg, Thermally Stable Poly(arylene ether) Dielectric forMicroelectronic Circuit Interconnect Process Integration: Synthesis,Characterization, Thermomechanical Properties, and Thin-Film ProcessingStudies,” Polymer Preprints, 37(1), 150 (1996), the disclosure of whichis totally incorporated herein by reference, discloses non-carbonylcontaining aromatic polyethers such as fluorinated poly(arylene ethers)based on decafluorobiphenyl as a class of intermetal dielectrics forapplications in sub-half micron multilevel interconnects.

J. J. Zupancic, D. C. Blazej, T. C. Baker, and E. A. Dinkel, “StyreneTerminated Resins as Interlevel Dielectrics for Multichip Models,”Polymer Preprints, 32, (2), 178 (1991), the disclosure of which istotally incorporated herein by reference, discloses vinylbenzyl ethersof polyphenols (styrene terminated resins) which were found to bephotochemically and thermally labile, generating highly crosslinkednetworks. The resins were found to yield no volatile by-products duringthe curing process and high glass transition, low dielectric constantcoatings. One of the resins was found to be spin coatable to varyingthickness coatings which could be photodefined, solvent developed, andthen hard baked to yield an interlevel dielectric.

Japanese Patent Kokai JP 04294148-A, the disclosure of which is totallyincorporated herein by reference, discloses a liquid injecting recordinghead containing the cured matter of a photopolymerizable compositioncomprising (1) a graft polymer comprising (A) alkyl methacrylate,acrylonitrile, and/or styrene as the trunk chain and an —OHgroup-containing acryl monomer, (B) amino or alkylamino group-containingacryl monomer, (C) carboxyl group-containing acryl or vinyl monomers,(D) N-vinyl pyrrolidone, vinyl pyridine or its derivatives, and/or (F)an acrylamide as the side chain; (2) a linear polymer containingconstitutional units derived from methyl methacrylate, ethylmethacrylate, isobutyl methacrylate, t-butyl methacrylate, benzylmethacrylate, acrylonitrile, isobornyl methacrylate, tricyclodecaneacrylate, tricyclodecane oxyethyl methacrylate, styrene,dimethylaminoethyl methacrylate, and/or cyclohexyl methacrylate, andconstitutional unit derived from the above compounds (A), (B), (C), (D),(E), or (F) above; (3) an ethylenic unsaturated bond containing monomer;and (4) a photopolymerization initiator which contains (a) an organicperoxide, s-triazine derivative, benzophenone or its derivatives,quinones, N-phenylglycine, and/or alkylarylketones as a radicalgenerator and (b) coumarin dyes, ketocoumarin dyes, cyanine dyes,merocyanine dyes, and/or xanthene dyes as a sensitizer.

“Functional Polymers and Sequential Copolymers by Phase TransferCatalysis, 2a: Synthesis and Characterization of Aromatic Poly(ethersulfone)s Containing Vinylbenzyl and Ethynylbenzyl Chain Ends,” V.Percec and B. C. Auman, Makromol Chem., 185, 1867-1880 (1984), thedisclosure of which is totally incorporated herein by reference,discloses a method for the synthesis of α,ω-bis(vinylbenzyl) aromaticpoly(ether sulfone)s and their transformation intoα,ω-bis(ethynylbenzyl) aromatic poly(ether sulfone)s. The method entailsa fast and quantitative Williamson etherification of theα,ω-bis(hydroxyphenyl) polysulfone with a mixture of p- andm-chloromethylstyrenes in the presence of tetrabutylammonium hydrogensulfate as phase transfer catalyst, a subsequent bromination, and then adehydrobromination with potassium tert-butoxide. The DSC study of thethermal curing of the α,ω-bis(vinylbenzyl) aromatic poly(ether sulfone)sand α,ω-bis(ethynylbenzyl) aromatic poly(ether sulfone)s demonstrateshigh thermal reactivity for the styrene-terminated oligomers.

“Functional Polymers and Sequential Copolymers by Phase TransferCatalysis, 3a: Synthesis and Characterization of Aromatic Poly(ethersulfone)s and Poly(oxy-2,6-dimethyl-1,4-phenylene) Containing PendentVinyl Groups,” V. Percec and B. C. Auman, Makromol. Chem., 185,2319-2336 (1984), the disclosure of which is totally incorporated hereinby reference, discloses a method for the syntheses of α,ω-benzylaromatic poly(ether sulfone)s (PSU) andpoly(oxy-2,6-dimethyl-1,4-phenylene) (POP) containing pendant vinylgroups. The first step of the synthetic procedure entails thechloromethylation of PSU and POP to provide polymers with chloromethylgroups. POP, containing bromomethyl groups, was obtained by radicalbromination of the methyl groups. Both chloromethylated andbromomethylated starting materials were transformed into theirphosphonium salts, and then subjected to a phase transfer catalyzedWittig reaction to provide polymers with pendant vinyl groups. A PSUwith pendant ethynyl groups was prepared by bromination of the PSUcontaining vinyl groups, followed by a phase transfer catalyzeddehydrobromination. DSC of the thermal curing of the polymers containingpendant vinyl and ethynyl groups showed that the curing reaction is muchfaster for the polymers containing vinyl groups. The resulting networkpolymers are flexible when the starting polymer contains vinyl groups,and very rigid when the starting polymer contains ethynyl groups.

“Functional Polymers and Sequential Copolymers by Phase TransferCatalysis,” V. Percec and P. L. Rinaldi, Polymer Bulletin, 10, 223(1983), the disclosure of which is totally incorporated herein byreference, discloses the preparation of p- andm-hydroxymethylphenylacetylenes by a two step sequence starting from acommercial mixture of p- and m-chloromethylstyrene, i.e., by thebromination of the vinylic monomer mixture followed by separation of m-and p-brominated derivatives by fractional crystallization, andsimultaneous dehydrobromination and nucleophilic substitution of the —Clwith —OH.

U.S. Pat. No. 4,110,279 (Nelson et al.), the disclosure of which istotally incorporated herein by reference, discloses a polymer derived byheating in the presence of an acid catalyst at between about 65° C. andabout 250° C.: I. a reaction product, a cogeneric mixture of alkoxyfunctional compounds, having average equivalent weights in the range offrom about 220 to about 1200, obtained by heating in the presence of astrong acid at about 50° C. to about 250° C.: (A) a diary compoundselected from naphthalene, diphenyl oxide, diphenyl sulfide, theiralkylated or halogenated derivatives, or mixtures thereof, (B)formaldehyde or formaldehyde yielding derivative, (C) water, and (D) ahydroxy aliphatic hydrocarbon compound having at least one free hydroxylgroup and from 1 to 4 carbon atoms, which mixture contains up to 50percent unreacted (A); with II. at least one monomeric phenolic reactantselected from the group

wherein R is selected from the group consisting of hydrogen, alkylradical of 1 to 20 carbon atoms, aryl radical of 6 to 20 carbon atoms,wherein R₁ represents hydrogen, alkyl, or aryl, m represents an integerfrom 1 to 3, o represents an integer from 1 to 5, p represents aninteger from 0 to 3, X represents oxygen, sulfur, or alkylidene, and qrepresents an integer from 0 to 1; and III. optionally an aldehyde oraldehyde-yielding derivative or ketone, for from several minutes toseveral hours. The polymeric materials are liquids or low melting solidswhich are capable of further modification to thermoset resins. Thesepolymers are capable of being thermoset by heating at a temperature offrom about 130° C. to about 260° C. for from several minutes to severalhours in the presence of a formaldehyde-yielding compound. Thesepolymers are also capable of further modification by reacting underbasic conditions with formaldehyde with or without a phenolic compound.The polymers, both base catalyzed resoles and acid catalyzed novolacs,are useful as laminating, molding, film-forming, and adhesive materials.The polymers, both resoles and novolacs, can be epoxidized as well asreacted with a drying oil to produce a varnish resin.

U.S. Pat. No 3,367,914 (Herbert), the disclosure of which is totallyincorporated herein by reference, discloses thermosetting resinousmaterials having melting points in the range of from 150° C. to 350° C.which are made heating at a temperature of from −10° C. to 100° C. for 5to 30 minutes an aldehyde such as formaldehyde or acetaldehyde with amixture of poly(aminomethyl) diphenyl ethers having an average of fromabout 1.5 to 4.0 aminomethyl groups. After the resins are cured underpressure at or above the melting point, they form adherent tough filmson metal substrates and thus are useful as wire coatings for electricalmagnet wire for high temperature service at 180° C. or higher.

J. S. Amato, S. Karady, M. Sletzinger, and L. M. Weinstock, “A NewPreparation of Chloromethyl Methyl Ether Free of Bis(chloromethyl)Ether,” Synthesis, 970 (1979), the disclosure of which is totallyincorporated herein by reference, discloses the synthesis ofchloromethyl methyl ether by the addition of acetyl chloride to a slightexcess of anhydrous dimethoxymethane containing a catalytic amount ofmethanol at room temperature. The methanol triggers a series ofreactions commencing with formation of hydrogen chloride and thereaction of hydrogen chloride with dimethoxymethane to form chloromethylmethyl ether and methanol in an equilibrium process. After 36 hours, anear-quantitative conversion to an equimolar mixture of chloromethylmethyl ether and methyl acetate is obtained.

A. McKillop, F. A. Madjdabadi, and D. A. Long, “A Simple and InexpensiveProcedure for Chloromethylation of Certain Aromatic Compounds,”Tetrahedron Letters, Vol. 24, No. 18, pp. 1933-1936 (1983), thedisclosure of which is totally incorporated herein by reference,discloses the reaction of a range of aromatic compounds withmethoxyacetyl chloride and aluminum chloride in either nitromethane orcarbon disulfide to result in chloromethylation in good to excellentyield.

E. P. Tepenitsyna, M. I. Farberov, and A. P. Ivanovskii, “Synthesis ofIntermediates for Production of Heat Resistant Polymers(Chloromethylation of Diphenyl Oxide),” Zhurnal Prikladnoi Khimii, Vol.40, No. 11, pp. 2540-2546 (1967), the disclosure of which is totallyincorporated herein by reference, discloses the chloromethylation ofdiphenyl oxide by (1) the action of paraformaldehyde solution in glacialacetic acid saturated with hydrogen chloride, and by (2) the action ofparaformaldehyde solution in concentrated hydrochloric acid.

U.S. Pat. No. 2,125,968 (Theimer), the disclosure of which is totallyincorporated herein by reference, discloses the manufacture of aromaticalcohols by the Friedel-Crafts reaction, in which an alkylene oxide iscondensed with a Friedel-Crafts reactant in the presence of an anhydrousmetal halide.

Copending application U.S. Ser. No. 08/705,914 filed Aug. 29, 1996,entitled “Thermal Ink Jet Printhead With Ink Resistant Heat SinkCoating,” with the named inventors Ram S. Narang and Timothy J. Fuller,the disclosure of which is totally incorporated herein by reference,discloses a heat sink for a thermal ink jet printhead having improvedresistance to the corrosive effects of ink by coating the surface of theheat sink with an ink resistant film formed by electrophoreticallydepositing a polymeric material on the heat sink surface. In onedescribed embodiment, a thermal ink jet printer is formed by bondingtogether a channel plate and a heater plate. Resistors and electricalconnections are formed in the surface of the heater plate. The heaterplate is bonded to a heat sink comprising a zinc substrate having anelectrophoretically deposited polymeric film coating. The film coatingprovides resistance to the corrosion of higher pH inks. In anotherembodiment, the coating has conductive fillers dispersed therethrough toenhance the thermal conductivity of the heat sink. In one embodiment,the polymeric material is selected from the group consisting ofpolyethersulfones, polysulfones, polyamides, polyimides,polyamide-imides, epoxy resins, polyetherimides, polyarylene etherketones, chloromethylated polyarylene ether ketones, acryloylatedpolyarylene ether ketones, polystyrene and mixtures thereof.

Copending application U.S. Ser. No. 08/703,138 filed Aug. 29, 1996entitled “Method for Applying an Adhesive Layer to a Substrate Surface,”with the named inventors Ram S. Narang, Stephen F. Pond, and Timothy J.Fuller, the disclosure of which is totally incorporated herein byreference, discloses a method for uniformly coating portions of thesurface of a substrate which is to be bonded to another substrate. In adescribed embodiment, the two substrates are channel plates and heaterplates which, when bonded together, form a thermal ink jet printhead.The adhesive layer is electrophoretically deposited over a conductivepattern which has been formed on the binding substrate surface. Theconductive pattern forms an electrode and is placed in anelectrophoretic bath comprising a colloidal emulsion of a preselectedpolymer adhesive. The other electrode is a metal container in which thesolution is placed or a conductive mesh placed within the container. Theelectrodes are connected across a voltage source and a field is applied.The substrate is placed in contact with the solution, and a smallcurrent flow is carefully controlled to create an extremely uniform thindeposition of charged adhesive micelles on the surface of the conductivepattern. The substrate is then removed and can be bonded to a secondsubstrate and cured. In one embodiment, the polymer adhesive is selectedfrom the group consisting of polyamides, polyimides, polyamide-imides,epoxy resins, polyetherimides, polysulfones, polyether sulfones,polyarylene ether ketones, polystyrenes, chloromethylated polyaryleneether ketones, acryloylated plyarylene ether ketones, and mixturesthereof.

Copending application U.S. Ser. No. 08/697,750 filed Aug. 29, 1996entitled “Electrophoretically Deposited Coating For the Front Face of anInk Jet Printhead,” with the named inventors Ram S. Narang, Stephen F.Pond, and Timothy J. Fuller, the disclosure of which is totallyincorporated herein by reference, discloses an electrophoreticdeposition technique for improving the hydrophobicity of a metalsurface, in one embodiment, the front face of a thermal ink jetprinthead. For this example, a thin metal layer is first deposited onthe front face. The front face is then lowered into a colloidal bathformed by a fluorocarbon-doped organic system dissolved in a solvent andthen dispersed in a non-solvent. An electric field is created and asmall amount of current through the bath causes negatively chargedparticles to be deposited on the surface of the metal coating. Bycontrolling the deposition time and current strength, a very uniformcoating of the fluorocarbon compound is formed on the metal coating. Theelectrophoretic coating process is conducted at room temperature andenables a precisely controlled deposition which is limited only to thefront face without intrusion into the front face orifices. In oneembodiment, the organic compound is selected from the group consistingof polyimides, polyamides, polyamide-imides, polysulfones, polyaryleneether ketones, polyethersulfones, polytetrafluoroethylenes,polyvinylidene fluorides, polyhexafluoro-propylenes, epoxies,polypentafluorostyrenes, polystyrenes, copolymers thereof, terpolymersthereof, and mixtures thereof.

Copending application U.S. Ser. No. 08/705,916, filed Aug. 29, 1996entitled “Stabilized Graphite Substrates,” with the named inventors GaryA. Kneezel, Ram S. Narang, Timothy J. Fuller, and Peter J. John, thedisclosure of which is totally incorporated herein by reference,discloses an apparatus which comprises at least one semiconductor chipmounted on a substrate, said substrate comprising a graphite memberhaving electrophoretically deposited thereon a coating of a polymericmaterial. In one embodiment, the semiconductor chips are thermal ink jetprinthead subunits. In one embodiment, the polymeric material is of thegeneral formula

wherein x is an integer of 0 or 1, A is one of several specified groups,such as

B is one of several specified groups, such as

or mixtures thereof, and n is an integer representing the number ofrepeating monomer units.

Copending application U.S. Ser. No. 08/705,375, filed Aug. 29, 1996entitled “Improved Curable Compositions,” with the named inventorsTimothy J. Fuller, Ram S. Narang, Thomas W. Smith, David J. Luca, andRalph A. Mosher, the disclosure of which is totally incorporated hereinby reference, discloses an improved composition comprising aphotopatternable polymer containing at least some monomer repeat unitswith photosensitivity-imparting substituents, said photopatternablepolymer being of the general formula

wherein x is an integer of 0 or 1, A is one of several specified groups,such as

B is one of several specified groups, such as

or mixtures thereof, and n is an integer representing the number ofrepeating monomer units. Also disclosed is a process for preparing athermal ink jet printhead with the aforementioned polymer and a thermalink jet printhead containing therein a layer of a crosslinked or chainextended polymer of the above formula.

Copending application U.S. Ser. No. 08/705,488 filed Aug. 29, 1996entitled “Improved High Performance Polymer Compositions,” with thenamed inventors Thomas W. Smith, Timothy J. Fuller, Ram S. Narang, andDavid J. Luca, the disclosure of which is totally incorporated herein byreference, discloses a composition comprising a polymer with a weightaverage molecular weight of from about 1,000 to about 65,000, saidpolymer containing at least some monomer repeat units with a first,photosensitivity-imparting substituent which enables crosslinking orchain extension of the polymer upon exposure to actinic radiation, saidpolymer also containing a second, thermal sensitivity-impartingsubstituent which enables further polymerization of the polymer uponexposure to temperatures of about 140° C. and higher, wherein the firstsubstituent is not the same as the second substituent, said polymerbeing selected from the group consisting of polysulfones,polyphenylenes, polyether sulfones, polyimides, polyamide imides,polyarylene ethers, polyphenylene sulfides, polyarylene ether ketones,phenoxy resins, polycarbonates, polyether imides, polyquinoxalines,polyquinolines, polybenzimidazoles, polybenzoxazoles,polybenzothiazoles, polyoxadiazoles, copolymers thereof, and mixturesthereof.

Copending application U.S. Ser. No. 08/697,761, filed Aug. 29, 1996entitled “Process for Direct Substitution of High Performance Polymerswith Unsaturated Ester Groups,” with the named inventors Timothy J.Fuller, Ram S. Narang, Thomas W. Smith, David J. Luca, and Raymond K.Crandall, the disclosure of which is totally incorporated herein byreference, discloses a process which comprises reacting a polymer of thegeneral formula

wherein x is an integer of 0 or 1, A is one of several specified groups,such as

B is one of several specified groups, such as

or mixtures thereof, and n is an integer representing the number ofrepeating monomer units, with (i) a formaldehyde source, and (ii) anunsaturated acid in the presence of an acid catalyst, thereby forming acurable polymer with unsaturated ester groups. Also disclosed is aprocess for preparing an ink jet printhead with the above polymer.

Copending application U.S. Ser. No. 08/705,463, filed Aug. 29, 1996entitled “Process for Haloalkylation of High Performance Polymers,” withthe named inventors Timothy J. Fuller, Ram S. Narang, Thomas W. Smith,David J. Luca, and Raymond K. Crandall, the disclosure of which istotally incorporated herein by reference, discloses a process whichcomprises reacting a polymer of the general formula

wherein x is an integer of 0 or 1, A is one of several specified groups,such as

B is one of several specified groups, such as

or mixtures thereof, and n is an integer representing the number ofrepeating monomer units, with an acetyl halide and dimethoxymethane inthe presence of a halogen-containing Lewis acid catalyst and methanol,thereby forming a haloalkylated polymer. In a specific embodiment, thehaloalkylated polymer is then reacted further to replace at least someof the haloalkyl groups with photosensitivity-imparting groups. Alsodisclosed is a process for preparing a thermal ink jet printhead withthe aforementioned polymer.

Copending application U.S. Ser. No. 08/705,479, filed Aug. 29, 1996entitled “Processes for Substituting Haloalkylated Polymers WithUnsaturated Ester, Ether, and Alkylcarboxymethylene Groups,” with thenamed inventors Timothy J. Fuller, Ram S. Narang, Thomas W. Smith, DavidJ. Luca, and Raymond K. Crandall, the disclosure of which is totallyincorporated herein by reference, discloses a process which comprisesreacting a haloalkylated aromatic polymer with a material selected fromthe group consisting of unsaturated ester salts, alkoxide salts,alkylcarboxylate salts, and mixtures thereof, thereby forming a curablepolymer having functional groups corresponding to the selected salt.Another embodiment of the invention is directed to a process forpreparing an ink jet printhead with the curable polymer thus prepared.

Copending application U.S. Ser. No. 08/705,371 filed Aug. 29, 1996entitled “Blends Containing Curable Polymers,” with the named inventorsRam S. Narang and Timothy J. Fuller, the disclosure of which is totallyincorporated herein by reference, discloses a composition whichcomprises a mixture of (A) a first component comprising a polymer, atleast some of the monomer repeat units of which have at least onephotosensitivity-imparting group thereon, said polymer having a firstdegree of photosensitivity-imparting group substitution measured inmilliequivalents of photosensitivity-imparting group per gram and beingof the general formula

wherein x is an integer of 0 or 1, A is one of several specified groups,such as

B is one of several specified groups, such as

or mixtures thereof, and n is an integer representing the number ofrepeating monomer units, and (B) a second component which compriseseither (1) a polymer having a second degree ofphotosensitivity-imparting group substitution measured inmilliequivalents of photosensitivity-imparting group per gram lower thanthe first degree of photosensitivity-imparting group substitution,wherein said second degree of photosensitivity-imparting groupsubstitution may be zero, wherein the mixture of the first component andthe second component has a third degree of photosensitivity-impartinggroup substitution measured in milliequivalents ofphotosensitivity-imparting group per gram which is lower than the firstdegree of photosensitivity-imparting group substitution and higher thanthe second degree of photosensitivity-imparting group substitution, or(2) a reactive diluent having at least one photosensitivity-impartinggroup per molecule and having a fourth degree ofphotosensitivity-imparting group substitution measured inmilliequivalents of photosensitivity-imparting group per gram, whereinthe mixture of the first component and the second component has a fifthdegree of photosensitivity-imparting group substitution measured inmilliequivalents of photosensitivity-imparting group per gram which ishigher than the first degree of photosensitivity-imparting groupsubstitution and lower than the fourth degree ofphotosensitivity-imparting group substitution; wherein the weightaverage molecular weight of the mixture is from about 10,000 to about50,000; and wherein the third or fifth degree ofphotosensitivity-imparting group substitution is from about 0.25 toabout 2 milliequivalents of photosensitivity-imparting groups per gramof mixture. Also disclosed is a process for preparing a thermal ink jetprinthead with the aforementioned composition.

Copending application U.S. Ser. No. 08/705,372, filed Aug. 29, 1996entitled “High Performance Curable Polymers and Processes for thePreparation Thereof,” with the named inventors Ram S. Narang and TimothyJ. Fuller, the disclosure of which is totally incorporated herein byreference, discloses a composition which comprises a polymer containingat least some monomer repeat units with photosensitivity-impartingsubstituents which enable crosslinking or chain extension of the polymerupon exposure to actinic radiation, said polymer being of the formula

wherein x is an integer of 0 or 1, A is one of several specified groups,such as

B is one of several specified groups, such as

or mixtures thereof, and n is an integer representing the number ofrepeating monomer units, wherein said photosensitivity-impartingsubstituents are allyl ether groups, epoxy groups, or mixtures thereof.Also disclosed are a process for preparing a thermal ink jet printheadcontaining the aforementioned polymers and processes for preparing theaforementioned polymers.

Copending application U.S. Ser. No. 08/705,460, filed Aug. 29, 1996,entitled “Halomethylated High Performance Curable Polymers,” with thenamed inventors Ram S. Narang and Timothy J. Fuller, the disclosure ofwhich is totally incorporated herein by reference, discloses a processwhich comprises the steps of (a) providing a polymer containing at leastsome monomer repeat units with halomethyl group substituents whichenable crosslinking or chain extension of the polymer upon exposure to aradiation source which is electron beam radiation, x-ray radiation, ordeep ultraviolet radiation, said polymer being of the formula

wherein x is an integer of 0 or 1, A is one of several specified groups,such as

B is one of several specified groups, such as

or mixtures thereof, and n is an integer representing the number ofrepeating monomer units, and (b) causing the polymer to becomecrosslinked or chain extended through the photosensitivity-impartinggroups. Also disclosed is a process for preparing a thermal ink jetprinthead by the aforementioned curing process.

Copending application U.S. Ser. No. 08/697,760, filed Aug. 29, 1996entitled “Aqueous Developable High Performance Curable Polymers,” withthe named inventors Ram S. Narang and Timothy J. Fuller, the disclosureof which is totally incorporated herein by reference, discloses acomposition which comprises a polymer containing at least some monomerrepeat units with water-solubility-imparting substituents and at leastsome monomer repeat units with photosensitivity-imparting substituentswhich enable crosslinking or chain extension of the polymer uponexposure to actinic radiation, said polymer being of the formula

wherein x is an integer of 0 or 1, A is one of several specified groups,such as

B is one of several specified groups, such as

or mixtures thereof, and n is an integer representing the number ofrepeating monomer units. In one embodiment, a single functional groupimparts both photosensitivity and water solubility to the polymer. Inanother embodiment, a first functional group imparts photosensitivity tothe polymer and a second functional group imparts water solubility tothe polymer. Also disclosed is a process for preparing a thermal ink jetprinthead with the aforementioned polymers.

While known compositions and processes are suitable for their intendedpurposes, a need remains for improved materials suitable formicroelectronics applications. A need also remains for improved ink jetprintheads. Further, there is a need for photopatternable polymericmaterials which are heat stable, electrically insulating, andmechanically robust. Additionally, there is a need for photopatternablepolymeric materials which are chemically inert with respect to thematerials that might be employed in ink jet ink compositions. There isalso a need for photopatternable polymeric materials which exhibit lowshrinkage during post-cure steps in microelectronic device fabricationprocesses. In addition, a need remains for photopatternable polymericmaterials which exhibit a relatively long shelf life. Further, there isa need for photopatternable polymeric materials which can be patternedwith relatively low photo-exposure energies. Additionally, a needremains for photopatternable polymeric materials which, in the curedform, exhibit good solvent resistance. There is also a need forphotopatternable polymeric materials which, when applied tomicroelectronic devices by spin casting techniques and cured, exhibitreduced edge bead and no apparent lips and dips. In addition, thereremains a need for processes for preparing photopatternable polymericmaterials with the above advantages. Further, a need remains forprocesses for preparing photopatternable polymeric materials with highaspect ratios at high resolutions by the incorporation of polymerizablegroups and/or cross-linking sites pendant to the polymers. Additionally,there is a need for processes for preparing aromatic polymers havingunsaturated ester functional groups pendant to the polymer chains. Thereis also a need for processes for preparing photopatternable polymershaving unsaturated ester functional groups pendant to the polymerchains. In addition, a need remains for photoresist materials which canbe patterned as thick 30 micron films which are resistant to alkalinemedia. Further, there is a need for photoresist materials which canserve as interlayer dielectrics at high temperatures. Additionally, aneed remains for photoresist materials which offer the advantage of noHCl liberation during thermal cure. In addition, there remains a needfor photopatternable polymeric materials which have relatively lowdielectric constants. Further, there is a need for photopatternablepolymeric materials which exhibit reduced water sorption. Additionally,a need remains for photopatternable polymeric materials which exhibitimproved hydrolytic stability, especially upon exposure to alkalinesolutions. A need also remains for photopatternable polymeric materialswhich are stable at high temperatures, typically greater than about 150°C. There is also a need for photopatternable polymeric materials whicheither have high glass transition temperatures or are sufficientlycrosslinked that there are no low temperature phase transitionssubsequent to photoexposure. Further, a need remains forphotopatternable polymeric materials with low coefficients of thermalexpansion. There is a need for polymers which are thermally stable,patternable as thick films of about 30 microns or more, exhibit lowT_(g) prior to photoexposure, have low dielectric constants, are low inwater absorption, have low coefficients of expansion, have desirablemechanical and adhesive characteristics, and are generally desirable forinterlayer dielectric applications, including those at hightemperatures, which are also photopatternable. There is also a need forphotoresist compositions with good to excellent processingcharacteristics.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide polymeric materialswith the above noted advantages.

It is another object of the present invention to provide improvedmaterials suitable for microelectronics applications.

It is yet another object of the present invention to provide improvedink jet printheads.

It is still another object of the present invention to providephotopatternable polymeric materials which are heat stable, electricallyinsulating, and mechanically robust.

Another object of the present invention is to provide photopatternablepolymeric materials which are chemically inert with respect to thematerials that might be employed in ink jet ink compositions.

Yet another object of the present invention is to providephotopatternable polymeric materials which exhibit low shrinkage duringpost-cure steps in microelectronic device fabrication processes.

Still another object of the present invention is to providephotopatternable polymeric materials which exhibit a relatively longshelf life.

It is another object of the present invention to providephotopatternable polymeric materials which can be patterned withrelatively low photo-exposure energies.

It is yet another object of the present invention to providephotopatternable polymeric materials which, in the cured form, exhibitgood solvent resistance.

It is still another object of the present invention to providephotopatternable polymeric materials which, when applied tomicroelectronic devices by spin casting techniques and cured, exhibitreduced edge bead and no apparent lips and dips.

Another object of the present invention is to provide processes forpreparing photopatternable polymeric materials with the aboveadvantages.

Yet another object of the present invention is to provide processes forpreparing photopatternable polymeric materials with high aspect ratiosat high resolutions by the incorporation of polymerizable groups and/orcross-linking sites pendant to the polymers.

Still another object of the present invention is to provide processesfor preparing aromatic polymers having unsaturated ester functionalgroups pendant to the polymer chains.

It is another object of the present invention to provide processes forpreparing photopatternable polymers having unsaturated ester functionalgroups pendant to the polymer chains.

It is yet another object of the present invention to provide photoresistmaterials which can be patterned as thick 30 micron films which areresistant to alkaline media.

It is still another object of the present invention to providephotoresist materials which can serve as interlayer dielectrics at hightemperatures.

Another object of the present invention is to provide photoresistmaterials which offer the advantage of no HCl liberation during thermalcure.

Yet another object of the present invention is to providephotopatternable polymeric materials which have relatively lowdielectric constants.

Still another object of the present invention is to providephotopatternable polymeric materials which exhibit reduced watersorption.

It is another object of the present invention to providephotopatternable polymeric materials which exhibit improved hydrolyticstability, especially upon exposure to alkaline solutions.

It is yet another object of the present invention to providephotopatternable polymeric materials which are stable at hightemperatures, typically greater than about 150° C.

It is still another object of the present invention to providephotopatternable polymeric materials which either have high glasstransition temperatures or are sufficiently crosslinked that there areno low temperature phase transitions subsequent to photoexposure.

Another object of the present invention is to provide photopatternablepolymeric materials with low coefficients of thermal expansion.

Yet another object of the present invention is to provide polymers whichare thermally stable, patternable as thick films of about 30 microns ormore, exhibit low T_(g) prior to photoexposure, have low dielectricconstants, are low in water absorption, have low coefficients ofexpansion, have desirable mechanical and adhesive characteristics, andare generally desirable for interlayer dielectric applications,including those at high temperatures, which are also photopatternable.

Still another object of the present invention is to provide photoresistcompositions with good to excellent processing characteristics.

These and other objects of the present invention (or specificembodiments thereof) can be achieved by providing a composition whichcomprises (a) a polymer containing at least some monomer repeat unitswith photosensitivity-imparting substituents which enable crosslinkingor chain extension of the polymer upon exposure to actinic radiation,said polymer being of the formula

wherein x is an integer of 0 or 1, A is

or mixtures thereof, B is

wherein v is an integer of from 1 to about 20,

wherein z is an integer of from 2 to about 20,

wherein u is an integer of from 1 to about 20,

wherein w is an integer of from 1 to about 20,

or mixtures thereof, and n is an integer representing the number ofrepeating monomer units, wherein said photosensitivity-impartingsubstituents are hydroxyalkyl groups; (b) at least one member selectedfrom the group consisting of photoinitiators and sensitizers; and (c) anoptional solvent. Another embodiment of the present invention isdirected to a process which comprises the steps of:

(a) depositing a layer comprising a polymer of the above formula onto alower substrate in which one surface thereof has an array of heatingelements and addressing electrodes having terminal ends formed thereon,said polymer being deposited onto the surface having the heatingelements and addressing electrodes thereon;

(b) exposing the layer to actinic radiation in an imagewise pattern suchthat the polymer in exposed areas becomes crosslinked or chain extendedand the polymer in unexposed areas does not become crosslinked or chainextended, wherein the unexposed areas correspond to areas of the lowersubstrate having thereon the heating elements and the terminal ends ofthe addressing electrodes;

(c) removing the polymer from the unexposed areas, thereby formingrecesses in the layer, said recesses exposing the heating elements andthe terminal ends of the addressing electrodes;

(d) providing an upper substrate with a set of parallel grooves forsubsequent use as ink channels and a recess for subsequent use as amanifold, the grooves being open at one end for serving as dropletemitting nozzles; and

(e) aligning, mating, and bonding the upper and lower substratestogether to form a printhead with the grooves in the upper substratebeing aligned with the heating elements in the lower substrate to formdroplet emitting nozzles, thereby forming a thermal ink jet printhead.Yet other embodiments of the present invention are directed to methodsfor preparing polymers of the above formula. Still other embodiments ofthe present invention are directed to crosslinked or chain extendedpolymers of the above formula, wherein the crosslinking or chainextension occurs through bisazide groups or urethane groups.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an enlarged schematic isometric view of an example of aprinthead mounted on a daughter board showing the droplet emittingnozzles.

FIG. 2 is an enlarged cross-sectional view of FIG. 1 as viewed along theline 2—2 thereof and showing the electrode passivation and ink flow pathbetween the manifold and the ink channels.

FIG. 3 is an enlarged cross-sectional view of an alternate embodiment ofthe printhead in FIG. 1 as viewed along the line 2—2 thereof.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to curable polymers havinghydroxyalkyl functional groups. The polymers are of the followingformula:

wherein x is an integer of 0 or 1, A is

—O—

—C(CH₃)₂—,

or mixtures thereof, B is

 CH₂_(v)

wherein v is an integer of from 1 to about 20, and preferably from 1 toabout 10,

wherein z is an integer of from 2 to about 20, and preferably from 2 toabout 10,

wherein u is an integer of from 1 to about 20, and preferably from 1 toabout 10,

wherein w is an integer of from 1 to about 20, and preferably from 1 toabout 10,

other similar bisphenol derivatives, or mixtures thereof, and n is aninteger representing the number of repeating monomer units. The value ofn is such that the weight average molecular weight of the material isfrom about 1,000 to about 100,000, preferably from about 1,000 to about65,000, more preferably from about 1,000 to about 40,000, and even morepreferably from about 3,000 to about 25,000, although the weight averagemolecular weight can be outside these ranges. Preferably, n is aninteger of from about 2 to about 70, more preferably from about 5 toabout 70, and even more preferably from about 8 to about 50, althoughthe value of n can be outside these ranges. The phenyl groups and the Aand/or B groups may also be substituted, although the presence of two ormore substituents on the B group ortho to the oxygen groups can rendersubstitution difficult. Substituents can be present on the polymereither prior to or subsequent to the placement ofphotosensitivity-imparting functional groups thereon. Substituents canalso be placed on the polymer during the process of placement ofphotosensitivity-imparting functional groups thereon. Examples ofsuitable substituents include (but are not limited to) alkyl groups,including saturated, unsaturated, and cyclic alkyl groups, preferablywith from 1 to about 6 carbon atoms, substituted alkyl groups, includingsaturated, unsaturated, and cyclic substituted alkyl groups, preferablywith from 1 to about 6 carbon atoms, aryl groups, preferably with from 6to about 24 carbon atoms, substituted aryl groups, preferably with from6 to about 24 carbon atoms, arylalkyl groups, preferably with from 7 toabout 30 carbon atoms, substituted arylalkyl groups, preferably withfrom 7 to about 30 carbon atoms, alkoxy groups, preferably with from 1to about 6 carbon atoms, substituted alkoxy groups, preferably with from1 to about 6 carbon atoms, aryloxy groups, preferably with from 6 toabout 24 carbon atoms, substituted aryloxy groups, preferably with from6 to about 24 carbon atoms, arylalkyloxy groups, preferably with from 7to about 30 carbon atoms, substituted arylalkyloxy groups, preferablywith from 7 to about 30 carbon atoms, hydroxy groups, amine groups,imine groups, ammonium groups, pyridine groups, pyridinium groups, ethergroups, ester groups, amide groups, carbonyl groups, thiocarbonylgroups, sulfate groups, sulfonate groups, sulfide groups, sulfoxidegroups, phosphine groups, phosphonium groups, phosphate groups, mercaptogroups, nitroso groups, sulfone groups, acyl groups, acid anhydridegroups, azide groups, and the like, wherein the substituents on thesubstituted alkyl groups, substituted aryl groups, substituted arylalkylgroups, substituted alkoxy groups, substituted aryloxy groups, andsubstituted arylalkyloxy groups can be (but are not limited to) hydroxygroups, amine groups, imine groups, ammonium groups, pyridine groups,pyridinium groups, ether groups, aldehyde groups, ketone groups, estergroups, amide groups, carboxylic acid groups, carbonyl groups,thiocarbonyl groups, sulfate groups, sulfonate groups, sulfide groups,sulfoxide groups, phosphine groups, phosphonium groups, phosphategroups, cyano groups, nitrile groups, mercapto groups, nitroso groups,halogen atoms, nitro groups, sulfone groups, acyl groups, acid anhydridegroups, azide groups, mixtures thereof, and the like, wherein two ormore substituents can be joined together to form a ring. Processes forthe preparation of these materials are known, and disclosed in, forexample, P. M. Hergenrother, J. Macromol. Sci. Rev. Macromol. Chem., C19(1), 1-34 (1980); P. M. Hergenrother, B. J. Jensen, and S. J. Havens,Polymer, 29, 358 (1988); B. J. Jensen and P. M. Hergenrother, “HighPerformance Polymers,” Vol. 1, No. 1) page 31 (1989), “Effect ofMolecular Weight on Poly(arylene ether ketone) Properties”; V. Percecand B. C. Auman, Makromol. Chem. 185, 2319 (1984); “High MolecularWeight Polymers by Nickel Coupling of Aryl Polychlorides,” I. Colon, G.T. Kwaiatkowski, J. of Polymer Science, Part A, Polymer Chemistry, 28,367 (1990); M. Ueda and T. Ito, Polymer J., 23 (4), 297 (1991);“Ethynyl-Terminated Polyarylates: Synthesis and Characterization,” S. J.Havens and P. M. Hergenrother, J. of Polymer Science: Polymer ChemistryEdition, 22, 3011 (1984); “Ethynyl-Terminated Polysulfones: Synthesisand Characterization,” P. M. Hergenrother, J. of Polymer Science:Polymer Chemistry Edition, 20, 3131 (1982); K. E. Dukes, M. D. Forbes,A. S. Jeevarajan, A. M. Belu, J. M. DeDimone, R. W. Linton, and V. V.Sheares, Macromolecules, 29, 3081 (1996); G. Hougham, G. Tesoro, and J.Shaw, Polym. Mater. Sci. Eng., 61, 369 (1989); V. Percec and B. C.Auman, Makromol. Chem, 185, 617 (1984); “Synthesis and characterizationof New Fluorescent Poly(arylene ethers),” S. Matsuo, N. Yakoh, S. Chino,M. Mitani, and S. Tagami, Journal of Polymer Science: Part A: PolymerChemistry, 32, 1071 (1994); “Synthesis of a Novel Naphthalene-BasedPoly(arylene ether ketone) with High Solubility and Thermal Stability,”Mami Ohno, Toshikazu Takata, and Takeshi Endo, Macromolecules, 27, 3447(1994); “Synthesis and Characterization of New Aromatic Poly(etherketones),” F. W. Mercer, M. T. Mckenzie, G. Merlino, and M. M. Fone, J.of Applied Polymer Science, 56, 1397 (1995); H. C. Zhang, T. L. Chen, Y.G. Yuan, Chinese Patent CN 85108751 (1991); “Static and laser lightscattering study of novel thermoplastics. 1. Phenolphthalein poly(arylether ketone), ” C. Wu, S. Bo, M. Siddiq, G. Yang and T. Chen,Macromolecules, 29, 2989 (1996); “Synthesis of t-Butyl-SubstitutedPoly(ether ketone) by Nickel-Catalyzed Coupling Polymerization ofAromatic Dichloride”, M. Ueda, Y. Seino, Y. Haneda, M. Yoneda, and J.-I.Sugiyama, Journal of Polymer Science: Part A: Polymer Chemistry, 32, 675(1994); “Reaction Mechanisms: Comb-Like Polymers and Graft Copolymersfrom Macromers 2. Synthesis, Characterzation and Homopolymerization of aStyrene Macromer of Poly(2,6-dimethyl-1,4-phenylene Oxide),” V. Percec,P. L. Rinaldi, and B. C. Auman, Polymer Bulletin, 10, 397 (1983);Handbook of Polymer Synthesis Part A, Hans R. Kricheldorf, ed., MarcelDekker, Inc., New York-Basel-Hong Kong (1992); and “Introduction ofCarboxyl Groups into Crosslinked Polystyrene,” C. R. Harrison, P. Hodge,J. Kemp, and G. M. Perry, Die Makromolekulare Chemie, 176, 267 (1975),the disclosures of each of which are totally incorporated herein byreference. Further background on high performance polymers is disclosedin, for example, U.S. Pat. Nos. 2,822,351; 3,065,205; British Patent1,060,546; British Patent 971,227; British Patent 1,078,234; U.S. Pat.No. 4,175,175; N. Yoda and H. Hiramoto, J. Macromol Sci. Chem., A21(13&14) pp. 1641 (1984) (Toray Industries, Inc., Otsu, Japan; B. Sillionand L. Verdet, “Polyimides and other High-Temperature polymers”, editedby M. J. M. Abadie and B. Sillion, Elsevier Science Publishers B. V.(Amsterdam 1991); “Polyimides with Alicyclic Diamines. II. HydrogenAbstraction and Photocrosslinking Reactions of Benzophenone TypePolyimides,” Q. Jin, T. Yamashita, and K. Horie, J. of Polymer Science:Part A: Polymer Chemistry, 32, 503 (1994); Probimide™ 300, productbulletin, Ciba-Geigy Microelectronics Chemicals, “PhotosensitivePolyimide System”; High Performance Polymers and Composites, J. I.Kroschwitz (ed.), John Wiley & Sons (New York 1991); and T. E. Atwood,D. A. Barr, T. A. King, B. Newton, and B. J. Rose, Polymer, 29, 358(1988), the disclosures of each of which are totally incorporated hereinby reference. Further information on radiation curing is disclosed in,for example, Radiation Curing: Science and Technology, S. Peter Pappas,ed., Plenum Press (New York 1992), the disclosure of which is totallyincorporated herein by reference.

For applications wherein the photopatternable polymer is to be used as alayer in a thermal ink jet printhead, the polymer preferably has anumber average molecular weight of from about 3,000 to about 20,000Daltons, more preferably from about 3,000 to about 10,000 Daltons, andeven more preferably from about 3,500 to about 6,500 Daltons, althoughthe molecular weight can be outside this range.

The polymer can be hydroxyalkylated at one or more sites, as follows:

wherein R is an alkyl group, including both saturated, unsaturated,linear, branched, and cyclic alkyl groups, preferably with from 1 toabout 11 carbon atoms, more preferably with from 1 to about 5 carbonatoms, even more preferably with from 1 to about 3 carbon atoms, andmost preferably with 1 carbon atom, or a substituted alkyl group,preferably with from 1 to about 11 carbon atoms, more preferably withfrom 1 to about 5 carbon atoms, even more preferably with from 1 toabout 3 carbon atoms, and most preferably with 1 carbon atom, and X is ahalogen atom, such as fluorine, chlorine, bromine, or iodine. Examplesof suitable substituents on the substituted alkyl group include (but arenot limited to) alkyl groups, including saturated, unsaturated, linear,branched, and cyclic alkyl groups, preferably with from 1 to about 6carbon atoms, substituted alkyl groups, preferably with from 1 to about6 carbon atoms, aryl groups, preferably with from 6 to about 24 carbonatoms, substituted aryl groups, preferably with from 6 to about 24carbon atoms, arylalkyl groups, preferably with from 7 to about 30carbon atoms, substituted arylalkyl groups, preferably with from 7 toabout 30 carbon atoms, alkoxy groups, preferably with from 1 to about 6carbon atoms, substituted alkoxy groups, preferably with from 1 to about6 carbon atoms, aryloxy groups, preferably with from 6 to about 24carbon atoms, substituted aryloxy groups, preferably with from 6 toabout 24 carbon atoms, arylalkyloxy groups, preferably with from 7 toabout 30 carbon atoms, substituted arylalkyloxy groups, preferably withfrom 7 to about 30 carbon atoms, amine groups, imine groups, ammoniumgroups, pyridine groups, pyridinium groups, ether groups, ester groups,amide groups, carbonyl groups, thiocarbonyl groups, sulfate groups,sulfonate groups, sulfide groups, sulfoxide groups, phosphine groups,phosphonium groups, phosphate groups, mercapto groups, nitroso groups,sulfone groups, acyl groups, acid anhydride groups, azide groups, andthe like, wherein the substituents on the substituted alkyl groups,substituted aryl groups, substituted arylalkyl groups, substitutedalkoxy groups, substituted aryloxy groups, and substituted arylalkyloxygroups can be (but are not limited to) hydroxy groups, amine groups,imine groups, ammonium groups, pyridine groups, pyridinium groups, ethergroups, aldehyde groups, ketone groups, ester groups, amide groups,carboxylic acid groups, carbonyl groups, thiocarbonyl groups, sulfategroups, sulfonate groups, sulfide groups, sulfoxide groups, phosphinegroups, phosphonium groups, phosphate groups, cyano groups, nitrilegroups, mercapto groups, nitroso groups, halogen atoms, nitro groups,sulfone groups, acyl groups, acid anhydride groups, azide groups,mixtures thereof, and the like, wherein two or more substituents can bejoined together to form a ring.

The hydroxymethylation of a polymer of the above formula can beaccomplished by reacting the polymer in solution with formaldehyde orparaformaldehyde and a base, such as sodium hydroxide, potassiumhydroxide, calcium hydroxide, ammonium hydroxide, tetramethylammoniumhydroxide, or the like. The polymer is dissolved in a suitable solvent,such as 1,1,2,2-tetrachloroethane or the like, and is allowed to reactwith the formaldehyde or paraformaldehyde. Examples of solvents suitablefor the reaction include 1,1,2,2-tetrachloroethane, as well as methylenechloride, provided a suitable pressure reactor is used. Typically, thereactants are present in relative amounts by weight of about 44.5 partsparaformaldehyde or 37 parts formaldehyde, about 1 part base, about 200parts 1,1,2,2-tetrachloroethane, and about 100 parts polymer.

The general reaction scheme is as follows:

wherein a, b, c, and d are each integers of 0, 1, 2, 3, or 4, providedthat at least one of a, b, c, and d is equal to or greater than 1 in atleast some of the monomer repeat units of the polymer, and n is aninteger representing the number of repeating monomer units. Substitutionis generally random, although the substituent often indicates apreference for the B group, and a particular preference for the sitesortho to oxygen on the B group, and any given monomer repeat unit mayhave no hydroxymethyl substituents, one hydroxymethyl substituent, ortwo or more hydroxymethyl substituents. Most commonly, each aromaticring will have either no hydroxymethyl groups or one hydroxymethylgroup.

Typical reaction temperatures are from about 50 to about 125° C., andpreferably from about 85 to about 110° C., although the temperature canbe outside these ranges. Typical reaction times are from about 4 toabout 24 hours, and preferably from about 4 to about 6 hours, althoughthe time can be outside these ranges. Longer reaction times generallyresult in higher degrees of hydroxymethylation. Different degrees ofhydroxymethylation may be desirable for different applications. Too higha degree of substitution may lead to excessive sensitivity, resulting incrosslinking or chain extension of both exposed and unexposed polymermaterial when the material is exposed imagewise to activating radiation,whereas too low a degree of substitution may be undesirable because ofresulting unnecessarily long exposure times or unnecessarily highexposure energies. For applications wherein the photopatternable polymeris to be used as a layer in a thermal ink jet printhead, the degree ofsubstitution (i.e., the average number of hydroxymethyl groups permonomer repeat unit) preferably is from about 0.25 to about 2.0, andmore preferably from about 0.5 to about 0.8, although the degree ofsubstitution can be outside these ranges for ink jet printheadapplications. This amount of substitution corresponds to from about 0.8to about 1.3 milliequivalents of hydroxymethyl per gram of resin.

Polymers of the above formula can also be hydroxyalkylated by firstpreparing the haloalkylated derivative and then replacing at least someof the haloalkyl groups with hydroxyalkyl groups. For example, thehaloalkylated polymer can be hydroxyalkylated by alkaline hydrolysis ofthe haloalkylated polymer. The hydroxy groups replace the halide atomsin the haloalkyl groups on the polymer; accordingly, the number ofcarbon atoms in the haloalkyl group generally corresponds to the numberof carbon atoms in the hydroxyalkyl group. Examples of suitablereactants include sodium hydroxide, potassium hydroxide, calciumhydroxide, ammonium hydroxide, tetraalkyl ammonium hydroxides, such astetrabutyl ammonium hydroxide, and the like. Examples of solventssuitable for the reaction include 1,1,2,2-tetrachloroethane, methylenechloride, and water. Typically, the reactants are, present in relativeamounts with respect to each other by weight of about 13.8 partshaloalkylated polymer, about 50 parts solvent, and about 30.6 parts base(containing 23 parts tetrabutylammonium hydroxide in water). After aclear solution is obtained, 30 milliliters of sodium hydroxide (50percent aqueous solution) is added. After 16 hours at about 25° C., theorganic layer is washed with water, dried over magnesium sulfate, andpoured into methanol (1 gallon) to precipitate the polymer.

The general reaction scheme, illustrated below for the chloromethylatedpolymer, is as follows:

wherein a, b, c, d, e, f, g, h, i, j, k, and m are each integers of 0,1, 2, 3, or 4, provided that the sum of i+e is no greater than 4, thesum of j+f is no greater than 4, the sum of k+g is no greater than 4,and the sum of m+h is no greater than 4, provided that at least one ofa, b, c, and d is equal to or greater than 1 in at least some of themonomer repeat units of the polymer, and provided that at least one ofe, f, g, and h is equal to at least 1 in at least some of the monomerrepeat units of the polymer, and n is an integer representing the numberof repeating monomer units.

Higher degrees of haloalkylation generally enable higher degrees ofsubstitution with hydroxyalkyl groups, and thereby enable greaterphotosensitivity of the polymer. Different degrees of substitution maybe desirable for different applications. Too high a degree ofsubstitution may lead to excessive sensitivity, resulting incrosslinking or chain extension of both exposed and unexposed polymermaterial when the material is exposed imagewise to activating radiation,whereas too low a degree of substitution may be undesirable because ofresulting unnecessarily long exposure times or unnecessarily highexposure energies. For applications wherein the photopatternable polymeris to be used as a layer in a thermal ink jet printhead, the degree ofsubstitution (i.e., the average number of hydroxyalkyl groups permonomer repeat unit) preferably is from about 0.25 to about 2.0, andmore preferably from about 0.5 to about 0.8, although the degree ofsubstitution can be outside these ranges for ink jet printheadapplications. Optimum amounts of substitution are from about 0.8 toabout 1.3 milliequivalents of hydroxyalkyl group per gram of resin.

Some or all of the haloalkyl groups can be replaced with hydroxyalkylsubstituents. Longer reaction times generally lead to greater degrees ofsubstitution of haloalkyl groups with hydroxyalkyl substituents.

Typical reaction temperatures are from about 25 to about 120° C., andpreferably from about 25 to about 50° C., although the temperature canbe outside this range. Typical reaction times are from about 1 to about24 hours, and preferably from about 10 to about 16 hours, although thetime can be outside these ranges.

The polymer to be substituted can be haloalkylated by any desired orsuitable process. For example, suitable processes for haloalkylatingpolymers include reaction of the polymers with formaldehyde andhydrohalic acid, bishalomethyl ether, halomethyl methyl ether,octylhalomethyl ether, or the like, generally in the presence of a Lewisacid catalyst. Bromination of a methyl group on the polymer can also beaccomplished with elemental bromine via a free radical process initiatedby, for example, a peroxide initiator or light. Halogen atoms can besubstituted for other halogens already on a halomethyl group by, forexample, reaction with the appropriate hydrohalic acid or halide salt.Methods for the halomethylation of polymers are also disclosed in, forexample, “Chloromethylation of Condensation Polymers Containing anoxy-1,4-phenylene Backbone,” W. H. Daly et al., Polymer Preprints, Vol.20, No. 1, 835 (1979), the disclosure of which is totally incorporatedherein by reference.

The haloalkylation of the polymer can be accomplished by reacting thepolymer with an acetyl halide and dimethoxymethane in the presence of ahalogen-containing Lewis acid catalyst such as those of the generalformula

M^(n⊕)X_(n)

wherein n is an integer of 1, 2, 3, 4, or 5, M represents a boron atomor a metal atom, such as tin, aluminum, zinc, antimony, iron (III),gallium, indium, arsenic, mercury, copper, platinum, palladium, or thelike, and X represents a halogen atom, such as fluorine, chlorine,bromine, or iodine, with specific examples including SnCl₄, AlCl₃,ZnCl₂, AlBr₃, BF₃, SbF₅, Fel₃, GaBr₃, InCl₃, Asl₅, HgBr₂, CuCl, PdCl₂,PtBr₂, or the like. Methanol is added to generate hydrohalic acidcatalytically; the hydrohalic acid reacts with dimethoxymethane to formhalomethyl methyl ether. Care must be taken to avoid cross-linking ofthe haloalkylated polymer. Typically, the reactants are present inrelative amounts by weight of about 35.3 parts acetyl halide, about 37parts dimethoxymethane, about 1.2 parts methanol, about 0.3 parts Lewisacid catalyst, about 446 parts 1,1,2,2-tetrachloroethane, and about 10to 20 parts polymer. 1,1,2,2-Tetrachlorethane is a suitable reactionsolvent. Dichloromethane is low boiling, and consequently the reactionis slow in this solvent unless suitable pressure equipment is used.

The general reaction scheme is as follows:

wherein R′ and R″ each, independently of the other, can be (but are notlimited to) hydrogen atoms, alkyl groups, including saturated,unsaturated, and cyclic alkyl groups, preferably with from 1 to about 11carbon atoms, substituted alkyl groups, preferably with from 1 to about11 carbon atoms, aryl groups, preferably with from 6 to about 11 carbonatoms, substituted aryl groups, preferably with from 6 to about 11carbon atoms, arylalkyl groups, preferably with from 7 to about 11carbon atoms, substituted arylalkyl groups, preferably with from 7 toabout 11 carbon atoms, and the like, and wherein R is an alkyl group,including both saturated, unsaturated, linear, branched, and cyclicalkyl groups, preferably with from 1 to about 11 carbon atoms, morepreferably with from 1 to about 5 carbon atoms, even more preferablywith from 1 to about 3 carbon atoms, and most preferably with 1 carbonatom, a substituted alkyl group, an arylalkyl group, preferably withfrom 7 to about 29 carbon atoms, more preferably with from 7 to about 17carbon atoms, even more preferably with from 7 to about 13 carbon atoms,and most preferably with from 7 to about 9 carbon atoms, or asubstituted arylalkyl group, and X is a halogen atom, such as fluorine,chlorine, bromine, or iodine. Examples of suitable substituents on thesubstituted alkyl, aryl, and arylalkyl groups include (but are notlimited to) alkyl groups, including saturated, unsaturated, linear,branched, and cyclic alkyl groups, preferably with from 1 to about 6carbon atoms, substituted alkyl groups, preferably with from 1 to about6 carbon atoms, aryl groups, preferably with from 6 to about 24 carbonatoms, substituted aryl groups, preferably with from 6 to about 24carbon atoms, arylalkyl groups, preferably with from 7 to about 30carbon atoms, substituted arylalkyl groups, preferably with from 7 toabout 30 carbon atoms, alkoxy groups, preferably with from 1 to about 6carbon atoms, substituted alkoxy groups, preferably with from 1 to about6 carbon atoms, aryloxy groups, preferably with from 6 to about 24carbon atoms, substituted aryloxy groups, preferably with from 6 toabout 24 carbon atoms, arylalkyloxy groups, preferably with from 7 toabout 30 carbon atoms, substituted arylalkyloxy groups, preferably withfrom 7 to about 30 carbon atoms, amine groups, imine groups, ammoniumgroups, pyridine groups, pyridinium groups, ether groups, ester groups,amide groups, carbonyl groups, thiocarbonyl groups, sulfate groups,sulfonate groups, sulfide groups, sulfoxide groups, phosphine groups,phosphonium groups, phosphate groups, mercapto groups, nitroso groups,sulfone groups, acyl groups, acid anhydride groups, azide groups, andthe like, wherein the substituents on the substituted alkyl groups,substituted aryl groups, substituted arylalkyl groups, substitutedalkoxy groups, substituted aryloxy groups, and substituted arylalkyloxygroups can be (but are not limited to) hydroxy groups, amine groups,imine groups, ammonium groups, pyridine groups, pyridinium groups, ethergroups, aldehyde groups, ketone groups, ester groups, amide groups,carboxylic acid groups, carbonyl groups, thiocarbonyl groups, sulfategroups, sulfonate groups, sulfide groups, sulfoxide groups, phosphinegroups, phosphonium groups, phosphate groups, cyano groups, nitrilegroups, mercapto groups, nitroso groups, halogen atoms, nitro groups,sulfone groups, acyl groups, acid anhydride groups, azide groups,mixtures thereof, and the like, wherein two or more substituents can bejoined together to form a ring. The resulting material is of the generalformula

wherein a, c, and d are each integers of 0, 1, 2, 3, or 4, provided thatat least one of a, b, c, and d is equal to or greater than 1 in at leastsome of the monomer repeat units of the polymer, and n is an integerrepresenting the number of repeating monomer units. Substitution isgenerally random, although the substituent often indicates a preferencefor the B group, and a particular preference for the sites ortho tooxygen on the B group, and any given monomer repeat unit may have nohaloalkyl substituents, one haloalkyl substituent, or two or morehaloalkyl substituents. Most commonly, each aromatic ring will haveeither no haloalkyl groups or one haloalkyl group.

Typical reaction temperatures are from about 60 to about 120° C., andpreferably from about 80 to about 110° C., although the temperature canbe outside these ranges. Typical reaction times are from about 1 toabout 10 hours, and preferably from about 2 to about 4 hours, althoughthe time can be outside these ranges. Longer reaction times generallyresult in higher degrees of haloalkylation. When the haloalkylatedpolymer is used as an intermediate material in the synthesis of polymerssubstituted with hydroxyalkyl groups, higher degrees of haloalkylationgenerally enable higher degrees of substitution with the desired groupand thereby enable greater photosensitivity of the polymer. Differentdegrees of haloalkylation may be desirable for different applications.When the material is used as an intermediate in the synthesis of thepolymer substituted with hydroxyalkyl groups, too high a degree ofsubstitution may lead to excessive sensitivity, resulting incrosslinking or chain extension of both exposed and unexposed polymermaterial when the material is exposed imagewise to activating radiation,whereas too low a degree of substitution may be undesirable because ofresulting unnecessarily long exposure times or unnecessarily highexposure energies. For applications wherein the photopatternable polymeris to be used as a layer in a thermal ink jet printhead, the degree ofsubstitution (i.e., the average number of hydroxyalkyl groups permonomer repeat unit) preferably is from about 0.5 to about 1.2, and morepreferably from about 0.7 to about 0.8, although the degree ofsubstitution can be outside these ranges for ink jet printheadapplications. This amount of substitution corresponds to from about 0.8to about 1.3 milliequivalents of hydroxyalkyl groups per gram of resin.When the haloalkyl groups are eventually to be substituted byhydroxyalkyl groups, the degree of haloalkylation is typically fromabout 0.25 to about 2, and, when it is desired to speed up thesubstitution reaction, preferably is from about 1 to about 2, and evenmore preferably from about 1.5 to about 2, although the degree ofhaloalkylation can be outside these ranges.

Other procedures for placing functional groups on aromatic polymers aredisclosed in, for example, W. H. Daly, S. Chotiwana, and R. Nielsen,Polymer Preprints, 20(1), 835 (1979); “Functional Polymers andSequential Copolymers by Phase Transfer Catalysis, 3. Synthesis AndCharacterization of Aromatic Poly(ether sulfone)s andPoly(oxy-2,6-dimethyl-1,4-phenylene) Containing Pendant Vinyl Groups,”V. Percec and B. C. Auman, Makromol Chem., 185, 2319 (1984); F. Wang andJ. Roovers, Journal of Polymer Science: Part A: Polymer Chemistry, 32,2413 (1994); “Details Concerning the Chloromethylation of Soluble HighMolecular Weight Polystyrene Using Dimethoxymethane, Thionyl Chloride,And a Lewis Acid: A Full Analysis,” M. E. Wright, E. G. Toplikar, and S.A. Svejda, Macromolecules, 24, 5879 (1991); “Functional Polymers andSequential Copolymers by Phase Transfer Catalysts,” V. Percec and P. L.Rinaldi, Polymer Bulletin, 10, 223 (1983); “Preparation of Polymer Resinand Inorganic Oxide Supported Peroxy-Acids and Their Use in theOxidation of Tetrahydrothiophene,” J. A. Greig, R. D. Hancock, and D. C.Sherrington, European Polymer J., 16, 293 (1980); “Preparation ofPoly(vinylbenzyltriphenylphosphonium Perbromide) and Its Application inthe Bromination of Organic Compounds,” A. Akelah, M. Hassanein, and F.Abdel-Galil, European Polymer J., 20 (3) 221 (1984); J. M. J. Frechetand K. K. Haque, Macromelcules, 8, 130 (1975); U.S. Pat. Nos. 3,914,194;4,110,279; 3,367,914; “Synthesis of Intermediates for Production of HeatResistant Polymers (Chloromethylation of Diphenyl oxide),” E. P.Tepenitsyna, M. I. Farberov, and A. P. Ivanovski, Zhurnal PrikladnoiKhimii, Vol. 40, No. 11, 2540 (1967); U.S. Pat. No. 3,000,839; ChemAbst. 56, 590f (1962); U.S. Pat. No. 3,128,258; Chem Abstr. 61, 4560a(1964); J. D. Doedens and H. P. Cordts, Ind. Eng. Ch., 83, 59 (1961);British Patent 863,702; and Chem Abstr 55, 18667b (1961); thedisclosures of each of which are totally incorporated herein byreference.

While not required, it may be advantageous with respect to the ultimateproperties of the photopatterned polymer if the polymer isfunctionalized with a second thermally polymerizable group, typically(although not necessarily) one which reacts at a temperature in excessof the glass transition temperature of the crosslinked photopatternablepolymer. The second polymerizable group can be either appended to thepolymer chain or present as a terminal end group.

Examples of suitable thermal sensitivity imparting groups includeethynyl groups, such as those of the formula

—(R)_(a)—C≡C—R′

wherein R is

a is an integer of 0 or 1, and R′ is a hydrogen atom or a phenyl group,ethylenic linkage-containing groups, such as allyl groups, includingthose of the formula

wherein X and Y each, independently of the other, are hydrogen atoms orhalogen atoms, such as fluorine, chlorine, bromine, or iodine, vinylgroups, including those of the formula

wherein R is an alkyl group, including both saturated, unsaturated,linear, branched, and cyclic alkyl groups, preferably with from 1 toabout 30 carbon atoms, more preferably with from 1 to about 11 carbonatoms, even more preferably with from 1 to about 5 carbon atoms, asubstituted alkyl group, an aryl group, preferably with from 6 to about24 carbon atoms, more preferably with from 6 to about 18 carbon atoms, asubstituted aryl group, an arylalkyl group, preferably with from 7 toabout 30 carbon atoms, more preferably with from 7 to about 19 carbonatoms, or a substituted arylalkyl group, wherein the substituents on thesubstituted alkyl groups, substituted aryl groups, substituted arylalkylgroups, substituted alkoxy groups, substituted aryloxy groups, andsubstituted arylalkyloxy groups can be (but are not limited to) hydroxygroups, amine groups, imine groups, ammonium groups, pyridine groups,pyridinium groups, ether groups, aldehyde groups, ketone groups, estergroups, amide groups, carboxylic acid groups, carbonyl groups,thiocarbonyl groups, sulfate groups, sulfonate groups, sulfide groups,sulfoxide groups, phosphine groups, phosphonium groups, phosphategroups, cyano groups, nitrile groups, mercapto groups, nitroso groups,halogen atoms, nitro groups, sulfone groups, acyl groups, acid anhydridegroups, azide groups, mixtures thereof, and the like, wherein any two ormore substituents can be joined together to form a ring, vinyl ethergroups, such as those of the formula

epoxy groups, including those of the formula

R is an alkyl group, including both saturated, unsaturated, linear,branched, and cyclic alkyl groups, preferably with from 1 to about 30carbon atoms, more preferably with from 1 to about 11 carbon atoms, evenmore preferably with from 1 to about 5 carbon atoms, a substituted alkylgroup, an aryl group, preferably with from 6 to about 24 carbon atoms,more preferably with from 6 to about 18 carbon atoms, a substituted arylgroup, an arylalkyl group, preferably with from 7 to about 30 carbonatoms, more preferably with from 7 to about 19 carbon atoms, or asubstituted arylalkyl group, wherein the substituents on the substitutedalkyl groups, substituted aryl groups, substituted arylalkyl groups,substituted alkoxy groups, substituted aryloxy groups, and substitutedarylalkyloxy groups can be (but are not limited to) hydroxy groups,amine groups, imine groups, ammonium groups, pyridine groups, pyridiniumgroups, ether groups, aldehyde groups, ketone groups, ester groups,amide groups, carboxylic acid groups, carbonyl groups, thiocarbonylgroups, sulfate groups, sulfonate groups, sulfide groups, sulfoxidegroups, phosphine groups, phosphonium groups, phosphate groups, cyanogroups, nitrile groups, mercapto groups, nitroso groups, halogen atoms,nitro groups, sulfone groups, acyl groups, acid anhydride groups, azidegroups, mixtures thereof, and the like, wherein any two or moresubstituents can be joined together to form a ring, halomethyl groups,such as fluoromethyl groups, chloromethyl groups, bromomethyl groups,and iodomethyl groups, hydroxymethyl groups, benzocyclobutene groups,including those of the formula

phenolic groups (φ-OH), provided that the phenolic groups are present incombination with either halomethyl groups or hydroxymethyl groups; thehalomethyl groups or hydroxymethyl groups can be present on the samepolymer bearing the phenolic groups or on a different polymer, or on amonomeric species present with the phenolic group substituted polymer;maleimide groups, such as those of the formula

biphenylene groups, such as those of the formula

5-norbornene-2,3dicarboximido (nadimido) groups, such as those of theformula

alkylcarboxylate groups, such as those of the formula

wherein R is an alkyl group (including saturated, unsaturated, andcyclic alkyl groups), preferably with from 1 to about 30 carbon atoms,more preferably with from 1 to about 6 carbon atoms, a substituted alkylgroup, an aryl group, preferably with from 6 to about 30 carbon atoms,more preferably with from 1 to about 2 carbon atoms, a substituted arylgroup, an arylalkyl group, preferably with from 7 to about 35 carbonatoms, more preferably with from 7 to about 15 carbon atoms, or asubstituted arylalkyl group, wherein the substituents on the substitutedalkyl, aryl, and arylalkyl groups can be (but are not limited to) alkoxygroups, preferably with from 1 to about 6 carbon atoms, aryloxy groups,preferably with from 6 to about 24 carbon atoms, arylalkyloxy groups,preferably with from 7 to about 30 carbon atoms, hydroxy groups, aminegroups, imine groups, ammonium groups, pyridine groups, pyridiniumgroups, ether groups, ester groups, amide groups, carbonyl groups,thiocarbonyl groups, sulfate groups, sulfonate groups, sulfide groups,sulfoxide groups, phosphine groups, phosphonium groups, phosphategroups, mercapto groups, nitroso groups, sulfone groups, acyl groups,acid anhydride groups, azide groups, and the like, wherein two or moresubstituents can be joined together to form a ring, and the like.

The thermal sensitivity imparting groups can be present either asterminal end groups on the polymer or as groups which are pendant fromone or more monomer repeat units within the polymer chain. When thethermal sensitivity imparting groups are present as terminal end groups,one or both polymer ends can be terminated with the thermal sensitivityimparting group (or more, if the polymer is crosslinked and has morethan two termini). When the thermal sensitivity imparting groups aresubstituents on one or more monomer repeat units of the polymer, anydesired or suitable degree of substitution can be employed. Preferably,the degree of substitution is from about 1 to about 4 thermalsensitivity imparting groups per repeat monomer unit, although thedegree of substitution can be outside this range. Preferably, the degreeof substitution is from about 0.5 to about 5 milliequivalents of thermalsensitivity imparting group per gram of polymer, and more preferablyfrom about 0.75 to about 1.5 milliequivalents per gram, although thedegree of substitution can be outside this range.

The thermal sensitivity imparting groups can be placed on the polymer byany suitable or desired synthetic method. Processes for putting theabove mentioned thermal sensitivity imparting groups on polymers aredisclosed in, for example, “Polyimides,” C. E. Sroog, Prog. Polym. Sci.,Vol. 16, 561-694 (1991); F. E. Arnold and L. S. Tan, Symposium on RecentAdvances in Polyimides and Other High Performance Polymers, Reno, Nev.(July 1987); L. S. Tan and F. E. Arnold, J. Polym. Sci. Part A, 26, 1819(1988); U.S. Pat. Nos. 4,973,636 and 4,927,907; the disclosures of eachof which are totally incorporated herein by reference.

Other procedures for placing thermally curable end groups on aromaticpolymers are disclosed in, for example, P. M. Hergenrother, J. Macromol.Sci. Rev. Macromol. Chem., C19 (1), 1-34 (1980); V. Percec and B. C.Auman, Makromol. Chem., 185, 2319 (1984); S. J. Havens, and P. M.Hergenrother, J. of Polymer Science: Polymer Chemistry Edition, 22, 3011(1984); P. M. Hergenrother, J. of Polymer Science: Polymer ChemistryEdition, 20, 3131 (1982); V. Percec, P. L. Rinaldi, and B. C. Auman,Polymer Bulletin, 10, 215 (1983); “Functional Polymers and SequentialCopolymers by Phase Transfer Catalysis, 2. Synthesis andCharacterization of Aromatic Poly(ether sulfones Containing Vinylbenzyland Ethynylbenzyl Chain Ends,” V. Percec and B. C. Auman, Makromol.Chem. 185, 1867 (1984); “Functional Polymers and Sequential Copolymersby Phase Transfer Catalysis, 6. On the Phase Transfer CatalyzedWilliamson Polyetherification as a New Method for the Preparation ofAlternating Block copolymers,” V. Percec, B. Auman, and P. L. Rinaldi,Polymer Bulletin, 10, 391 (1983); “Functional Polymers and SequentialCopolymers by Phase Transfer Catalysis, 3 Synthesis and Characterizationof Aromatic Poly(ether sulfone)s andPoly(oxy-2,6-dimethyl-1,4-phenylene) Containing Pendant Vinyl Groups,”V. Percec and B. C. Auman, Makromol. Chem., 185, 2319 (1984); and “PhaseTransfer Catalysis, Functional Polymers and Sequential Copolymers byPTC,5. Synthesis and Characterization of Polyformals of PolyetherSulfones,” Polymer Bulletin, 10, 385 (1983); the disclosures of each ofwhich are totally incorporated herein by reference.

In some instances a functional group can behave as either aphotosensitivity-imparting group or a thermal sensitivity impartinggroup. For the polymers of the present invention having optional thermalsensitivity imparting groups thereon, at least two different groups arepresent on the polymer, one of which functions as aphotosensitivity-imparting group and one of which functions as a thermalsensitivity imparting group. Either the two groups are selected so thatthe thermal sensitivity imparting group does not react or crosslink whenexposed to actinic radiation at a level to which thephotosensitivity-imparting group is sensitive, or photocuring is haltedwhile at least some thermal sensitivity imparting groups remain intactand unreacted or uncrosslinked on the polymer. Typically (although notnecessarily) the thermal sensitivity imparting group is one which reactsat a temperature in excess of the glass transition temperature of thepolymer subsequent to crosslinking or chain extension via photoexposure.

When thermal sensitivity imparting groups are present, the polymers ofthe present invention are cured in a two-stage process which entails (a)exposing the polymer to actinic radiation, thereby causing the polymerto become crosslinked or chain extended through thephotosensitivity-imparting groups; and (b) subsequent to step (a),heating the polymer to a temperature of at least 140° C., therebycausing further crosslinking or chain extension of the polymer throughthe thermal sensitivity imparting groups.

The temperature selected for the second, thermal cure step generallydepends on the thermal sensitivity imparting group which is present onthe polymer. For example, ethynyl groups preferably are cured attemperatures of from about 150 to about 300° C. Halomethyl groupspreferably are cured at temperatures of from about 150 to about 260° C.Hydroxymethyl groups preferably are cured at temperatures of from about150 to about 250° C. Phenylethynyl phenyl groups preferably are cured attemperatures of about 350° C. Vinyl groups preferably are cured attemperatures of from about 150 to about 250° C. Allyl groups preferablyare cured at temperatures of over about 260° C. Epoxy groups preferablyare cured at temperatures of about 150° C. Maleimide groups preferablyare cured at temperatures of from about 300 to about 350° C.Benzocyclobutene groups preferably are cured at temperatures of overabout 300° C. 5-Norbornene-2,3-dicarboximido groups preferably are curedat temperatures of from about 250 to about 350° C. Vinyl ether groupspreferably are cured at temperatures of about 150° C. Phenolic groups inthe presence of hydroxymethyl or halomethyl groups preferably are curedat temperatures of from about 150 to about 180° C. Alkylcarboxylategroups preferably are cured at temperatures of from about 150 to about250° C. Curing temperatures usually do not exceed 350 or 400° C.,although higher temperatures can be employed provided that decompositionof the polymer does not occur. Higher temperature cures preferably takeplace in an oxygen-excluded environment.

Reaction of the phenylethynyl end groups serves to chain-extend thenetwork. Hydroxymethyl and halo groups are also preferred when thephotopatternable polymer has a glass transition temperature of less thanabout 150° C. Hydroxymethyl and halomethyl groups on phenolic ends areparticularly reactive and serve to chain-extend the network. The factthat this chain extension occurs at temperatures significantly in excessof the glass transition temperature of the polymer facilitates the chainextension reaction, relaxes stresses in the crosslinked film, and allowsfor the extrusion of thermally labile alkyl fragments introduced in thephotoactivation of the backbone. Phenolic end groups can be obtained byadjusting the stoichiometry of the coupling reaction in the formation ofpolyarylene ether ketones; for example, excess bisphenol A is used whenbisphenol A is the B group. Halomethyl groups are particularlypreferred. Halomethyl groups react at a temperature in excess of 150° C.and extensively crosslink the polymer by the elimination of hydrochloricacid and the formation of methylene bridges. When the photoexposedcrosslinked polymer has a glass transition temperature of less thanabout 150° C., halomethyl groups are particularly preferred. The factthat this chain extension and crosslinking occurs at temperaturessignificantly in excess of the glass transition temperature of thepolymer facilitates the chain extension reaction, relaxes stresses inthe cross-linked film, and allows for the extrusion of thermally labilealkyl fragments introduced in the photoactivation of the backbone. Thethermal reaction is believed to eliminate hydrohalic acid and to linkpolymer chains with methylene bridges. Crosslinking of the halomethylgroups begins near 150° C. and proceeds rapidly in the temperature rangeof from about 180 to about 210° C.

Further information regarding photoresist compositions is disclosed in,for example, J. J. Zupancic, D. C. Blazej, T. C. Baker, and E. A.Dinkel, Polymer Preprints, 32, (2), 178 (1991); “High PerformanceElectron Negative Resist, Chloromethylated Polystyrene. A Study onMolecular Parameters,” S. Imamura, T. Tamamura, and K. Harada, J. ofApplied Polymer Science, 27, 937 (1982); “Chloromethylated Polystyreneas a Dry Etching-Resistant Negative Resist for Submicron Technology”, S.Imamura, J. Electrochem. Soc.: Solid-state Science and Technology,126(9), 1628 (1979); “UV curing of composites based on modifiedunsaturated polyesters,” W. Shi and B. Ranby, J. of Applied PolymerScience, Vol. 51, 1129 (1994); “Cinnamates VI. Light-Sensitive Polymerswith Pendant o-,m- and p-hydroxycinnamate Moieties,” F. Scigalski, M.Toczek, and J. Paczkowski, Polymer, 35, 692 (1994); and “Radiation-curedPolyurethane Methacrylate Pressure-sensitive Adhesives,” G. Ansell andC. Butler, Polymer, 35 (9), 2001 (1994), the disclosures of each ofwhich are totally incorporated herein by reference.

In some instances, the terminal groups on the polymer can be selected bythe stoichiometry of the polymer synthesis. For example, when a polymeris prepared by the reaction of 4,4′-dichlorobenzophenone and bis-phenolA in the presence of potassium carbonate in N,N-dimethylacetamide, ifthe bis-phenol A is present in about 7.5 to 8 mole percent excess, theresulting polymer generally is bis-phenol A-terminated (wherein thebis-phenol A moiety may or may not have one or more hydroxy groupsthereon), and the resulting polymer typically has a polydispersity(M_(w)/M_(n)) of from about 2 to about 3.5. When the bis-phenolA-terminated polymer is subjected to further reactions to placefunctional groups thereon, such as haloalkyl groups, and/or to convertone kind of functional group, such as a haloalkyl group, to another kindof functional group, such as an unsaturated ester group, thepolydispersity of the polymer can rise to the range of from about 4 toabout 6. In contrast, if the 4,4′-dichlorobenzophenone is present inabout 7.5 to 8 mole percent excess, the reaction time is approximatelyhalf that required for the bis-phenol A excess reaction, the resultingpolymer generally is benzophenone-terminated (wherein the benzophenonemoiety may or may not have one or more chlorine atoms thereon), and theresulting polymer typically has a polydispersity of from about 2 toabout 3.5. When the benzophenone-terminated polymer is subjected tofurther reactions to place functional groups thereon, such as haloalkylgroups, and/or to convert one kind of functional group, such as ahaloalkyl group, to another kind of functional group, such as ahydroxymethyl group, the polydispersity of the polymer typically remainsin the range of from about 2 to about 3.5. Similarly, when a polymer isprepared by the reaction of 4,4′-difluorobenzophenone with either9,9′-bis(4-hydroxyphenyl)fluorene or bis-phenol A in the presence ofpotassium carbonate in N,N-dimethylacetamide, if the4,4′-difluorobenzophenone reactant is present in excess, the resultingpolymer generally has benzophenone terminal groups (which may or may nothave one or more fluorine atoms thereon). The well-known Carothersequation can be employed to calculate the stoichiometric offset requiredto obtain the desired molecular weight. (See, for example, William H.Carothers, “An Introduction to the General Theory of CondensationPolymers,” Chem. Rev., 8, 353 (1931) and J. Amer. Chem. Soc., 51, 2548(1929); see also P. J. Flory, Principles of Polymer Chemistry, CornellUniversity Press, Ithaca, N.Y. (1953); the disclosures of each of whichare totally incorporated herein by reference.) More generally speaking,during the preparation of polymers of the formula

the stoichiometry of the polymer synthesis reaction can be adjusted sothat the end groups of the polymer are derived from the “A” groups orderived from the “B” groups. Specific functional groups can also bepresent on these terminal “A” groups or “B” groups, such as ethynylgroups or other thermally sensitive groups, hydroxy groups which areattached to the aromatic ring on an “A” or “B” group to form a phenolicmoiety, halogen atoms which are attached to the “A” or “B” group, or thelike.

Polymers with end groups derived from the “A” group, such asbenzophenone groups or halogenated benzophenone groups, may be preferredfor some applications because both the syntheses and some of thereactions of these materials to place substituents thereon may be easierto control and may yield better results with respect to, for example,cost, molecular weight, molecular weight range, and polydispersity(M_(w)/M_(n)) compared to polymers with end groups derived from the “B”group, such as bis-phenol A groups (having one or more hydroxy groups onthe aromatic rings thereof) or other phenolic groups. While not beinglimited to any particular theory, it is believed that the haloalkylationreaction in particular proceeds most rapidly on the phenolic tails whenthe polymer is bis-phenol A terminated. Moreover, it is believed thathalomethylated groups on phenolic-terminated polymers may beparticularly reactive to subsequent crosslinking or chain extension. Incontrast, it is generally believed that halomethylation does not takeplace on the terminal aromatic groups with electron withdrawingsubstituents, such as benzophenone, halogenated benzophenone, or thelike. The “A” group terminated materials may also function as anadhesive, and in applications such as thermal ink jet printheads, theuse of the crosslinked “A” group terminated polymer may reduce oreliminate the need for an epoxy adhesive to bond the heater plate to thechannel plate.

If desired, to reduce the amount of residual halogen in a photoresist orother composition containing the polymers of the present invention,thereby also reducing or eliminating the generation of hydrohalic acidduring a subsequent thermal curing step, any residual halogen atoms orhaloalkyl groups on the photopatternable polymer can be converted tomethoxy groups, hydroxide groups, acetoxy groups, amine groups, or thelike by any desired process, including those processes disclosedhereinabove, those disclosed in, for example, British Patent 863,702,Chem Abstr. 55, 18667b (1961), and other publications previouslyincorporated herein by reference, and the like.

The photopatternable polymer can be cured by uniform exposure to actinicradiation at wavelengths and/or energy levels capable of causingcrosslinking or chain extension of the polymer through thephotosensitivity-imparting groups. Alternatively, the photopatternablepolymer is developed by imagewise exposure of the material to radiationat a wavelength and/or at an energy level to which thephotosensitivity-imparting groups are sensitive. Typically, aphotoresist composition will contain the photopatternable polymer, anoptional solvent for the photopatternable polymer, an optionalsensitizer, and an optional photoinitiator. Solvents may be particularlydesirable when the uncrosslinked photopatternable polymer has a highT_(g). The solvent and photopatternable polymer typically are present inrelative amounts of from 0 to about 99 percent by weight solvent andfrom about 1 to 100 percent polymer, preferably are present in relativeamounts of from about 20 to about 60 percent by weight solvent and fromabout 40 to about 80 percent by weight polymer, and more preferably arepresent in relative amounts of from about 30 to about 60 percent byweight solvent and from about 40 to about 70 percent by weight polymer,although the relative amounts can be outside these ranges.

Sensitizers absorb light energy and facilitate the transfer of energy tounsaturated bonds which can then react to crosslink or chain extend theresin. Sensitizers frequently expand the useful energy wavelength rangefor photoexposure, and typically are aromatic light absorbingchromophores. Sensitizers can also lead to the formation ofphotoinitiators, which can be free radical or ionic. When present, theoptional sensitizer and the photopatternable polymer typically arepresent in relative amounts of from about 0.1 to about 20 percent byweight sensitizer and from about 80 to about 99.9 percent by weightphotopatternable polymer, and preferably are present in relative amountsof from about 1 to about 10 percent by weight sensitizer and from about90 to about 99 percent by weight photopatternable polymer, although therelative amounts can be outside these ranges.

Photoinitiators generally generate ions or free radicals which initiatepolymerization upon exposure to actinic radiation. When present, theoptional photoinitiator and the photopatternable polymer typically arepresent in relative amounts of from about 0.1 to about 20 percent byweight photoinitiator and from about 80 to about 99.9 percent by weightphotopatternable polymer, and preferably are present in relative amountsof from about 1 to about 10 percent by weight photoinitiator and fromabout 90 to about 99 percent by weight photopatternable polymer,although the relative amounts can be outside these ranges.

A single material can also function as both a sensitizer and aphotoinitiator.

Examples of specific sensitizers and photoinitiators include Michler'sketone (Aldrich Chemical Co.), Darocure 1173, Darocure 4265, Irgacure184, Irgacure 261, and Irgacure 907 (available from Ciba-Geigy, Ardsley,N.Y.), and mixtures thereof. Further background material on initiatorsis disclosed in, for example, Ober et al., J.M.S.—Pure Appl. Chem., A30(12), 877-897 (1993); G. E. Green, B. P. Stark, and S. A. Zahir,“Photocrosslinkable Resin Systems,” J. Macro. Sci.—Revs. Macro. Chem.,C21(2), 187 (1981); H. F. Gruber, “Photoinitiators for Free RadicalPolymerization,” Prog. Polym. Sci., Vol. 17, 953 (1992); Johann G.Kloosterboer, “Network Formation by Chain CrosslinkingPhotopolymerization and Its Applications in Electronics,” Advances inPolymer Science, 89, Springer-Verlag Berlin Heidelberg (1988); and“Diaryliodonium Salts as Thermal Initiators of Cationic Polymerization,”J. V. Crivello, T. P. Lockhart, and J. L. Lee, J. of Polymer Science:Polymer Chemistry Edition, 21, 97 (1983), the disclosures of each ofwhich are totally incorporated herein by reference. Sensitizers areavailable from, for example, Aldrich Chemical Co., Milwaukee, Wis., andPfaltz and Bauer, Waterberry, Conn. Benzophenone and its derivatives canfunction as photosensitizers. Triphenylsulfonium and diphenyl iodoniumsalts are examples of typical cationic photoinitiators.

Inhibitors may also optionally be present in the photoresist containingthe photopatternable polymer. Examples of suitable inhibitors includeMEHQ, a methyl ether of hydroquinone, of the formula

t-butylcatechol, of the formula

hydroquinone, of the formula

and the like, the inhibitor typically present in an amount of from about500 to about 1,500 parts per million by weight of a photoresist solutioncontaining about 40 percent by weight polymer solids, although theamount can be outside this range.

One specific example of a class of sensitizers or initiators suitablefor the polymers of the present invention is that of bis(azides), of thegeneral formula

wherein R is

wherein R₁, R₂, R₃, and R₄ each, independently of the others, is ahydrogen atom, an alkyl group, including saturated, unsaturated, andcyclic alkyl groups, preferably with from 1 to about 30 carbon atoms,and more preferably with from 1 to about 6 carbon atoms, a substitutedalkyl group, an aryl group, preferably with from 6 to about 18 carbonatoms, and more preferably with about 6 carbon atoms, a substituted arylgroup, an arylalkyl group, preferably with from 7 to about 48 carbonatoms, and more preferably with from about 7 to about 8 carbon atoms, ora substituted arylalkyl group, and x is 0 or 1, wherein the substituentson the substituted alkyl, aryl, and aryl groups can be (but are notlimited to) alkyl groups, including saturated, unsaturated, linear,branched, and cyclic alkyl groups, preferably with from 1 to about 6carbon atoms, substituted alkyl groups, preferably with from 1 to about6 carbon atoms, aryl groups, preferably with from 6 to about 24 carbonatoms, substituted aryl groups, preferably with from 6 to about 24carbon atoms, arylalkyl groups, preferably with from 7 to about 30carbon atoms, substituted arylalkyl groups, preferably with from 7 toabout 30 carbon atoms, alkoxy groups, preferably with from 1 to about 6carbon atoms, substituted alkoxy groups, preferably with from 1 to about6 carbon atoms, aryloxy groups, preferably with from 6 to about 24carbon atoms, substituted aryloxy groups, preferably with from 6 toabout 24 carbon atoms, arylalkyloxy groups, preferably with from 7 toabout 30 carbon atoms, substituted arylalkyloxy groups, preferably withfrom 7 to about 30 carbon atoms, amine groups, imine groups, ammoniumgroups, pyridine groups, pyridinium groups, ether groups, ester groups,amide groups, carbonyl groups, thiocarbonyl groups, sulfate groups,sulfonate groups, sulfide groups, sulfoxide groups, phosphine groups,phosphonium groups, phosphate groups, mercapto groups, nitroso groups,sulfone groups, acyl groups, acid anhydride groups, azide groups, andthe like, wherein the substituents on the substituted alkyl groups,substituted aryl groups, substituted arylalkyl groups, substitutedalkoxy groups, substituted aryloxy groups, and substituted arylalkyloxygroups can be (but are not limited to) hydroxy groups, amine groups,imine groups, ammonium groups, pyridine groups, pyridinium groups, ethergroups, aldehyde groups, ketone groups, ester groups, amide groups,carboxylic acid groups, carbonyl groups, thiocarbonyl groups, sulfategroups, sulfonate groups, sulfide groups, sulfoxide groups, phosphinegroups, phosphonium groups, phosphate groups, cyano groups, nitrilegroups, mercapto groups, nitroso groups, halogen atoms, nitro groups,sulfone groups, acyl groups, acid anhydride groups, azide groups,mixtures thereof, and the like, wherein any two or more substituents canbe joined together to form a ring. Examples of suitable bis(azides)include 4,4′-diazidostilbene, of the formula

4,4′-diazidobenzophenone, of the formula

2,6-di-(4′-azidobenzal)-4-methylcyclohexanone, of the formula

4,4′-diazidobenzalacetone, of the formula

and the like. While not being limited to any particular theory, it isbelieved that exposure to, for example, ultraviolet radiation enablescuring, as illustrated below for the hydroxymethylated polymer:

wherein X and X′ each, independently of the other, is —H or —OH.

Alternatively, a hydroxyalkylated polymer can be further reacted torender it more photosensitive. For example, a hydroxymethylated polymerof the formula

can react with an unsaturated ester isocyanate, typically of the generalformula

wherein R₁ is an unsaturated alkyl group (which may be cyclic, branched,or linear), typically with from 1 to about 11 carbon atoms, or anunsaturated arylalkyl group, typically with from 7 to about 18 carbonatoms, and R₂ is an alkyl group (and may be either saturated orunsaturated, cyclic, branched, or linear), typically with from 1 toabout 11 carbon atoms, or an arylalkyl group (and may be eithersaturated or unsaturated, cyclic, branched, or linear), typically withfrom 7 to about 18 carbon atoms, with specific examples includingisocyanato ethyl acrylate, isocyanato ethyl cinnamate, isocyanato-ethylmethacrylate, of the formula

(available from Polysciences, Warrington, Pa.), other isocyanato alkylunsaturated esters, or the like. A photoactive polymer is then formed,of, for the specific example with isocyanato ethyl methacrylate, theformula

This reaction can be carried out in methylene chloride at 25° C. with 1part by weight polymer, 1 part by weight isocyanato-ethyl methacrylate,and 50 parts by weight methylene chloride. Typical reaction temperaturesare from about 0 to about 50° C., with 10 to 25° C. preferred. Typicalreaction times are between about 1 and about 24 hours, with about 16hours preferred. While not being limited to any particular theory, it isbelieved that during exposure to, for example, ultraviolet radiation,the ethylenic bond opens and crosslinking or chain extension occurs atthat site. The crosslinks or chain extensions formed are believed to bevia groups of the general formula

wherein R₁ is an alkyl group (which may be cyclic, branched, or linear),typically with from 1 to about 11 carbon atoms, or an arylalkyl group,typically with from 7 to about 18 carbon atoms, R₂ is an alkyl group(and may be either saturated or unsaturated, cyclic, branched, orlinear), typically with from 1 to about 11 carbon atoms, or an arylalkylgroup, typically with from 7 to about 18 carbon atoms, and R₃ is analkyl group, including both saturated, unsaturated, linear, branched,and cyclic alkyl groups, preferably with from 1 to about 11 carbonatoms, more preferably with from 1 to about 5 carbon atoms, even morepreferably with from 1 to about 3 carbon atoms, and most preferably with1 carbon atom, or a substituted alkyl group, preferably with from 1 toabout 11 carbon atoms, more preferably with from 1 to about 5 carbonatoms, even more preferably with from 1 to about 3 carbon atoms, andmost preferably with 1 carbon atom, and X is a halogen atom, such asfluorine, chlorine, bromine, or iodine. Examples of suitablesubstituents on the substituted alkyl group include (but are not limitedto) alkyl groups, including saturated, unsaturated, linear, branched,and cyclic alkyl groups, preferably with from 1 to about 6 carbon atoms,substituted alkyl groups, preferably with from 1 to about 6 carbonatoms, aryl groups, preferably with from 6 to about 24 carbon atoms,substituted aryl groups, preferably with from 6 to about 24 carbonatoms, arylalkyl groups, preferably with from 7 to about 30 carbonatoms, substituted arylalkyl groups, preferably with from 7 to about 30carbon atoms, alkoxy groups, preferably with from 1 to about 6 carbonatoms, substituted alkoxy groups, preferably with from 1 to about 6carbon atoms, aryloxy groups, preferably with from 6 to about 24 carbonatoms, substituted aryloxy groups, preferably with from 6 to about 24carbon atoms, arylalkyloxy groups, preferably with from 7 to about 30carbon atoms, substituted arylalkyloxy groups, preferably with from 7 toabout 30 carbon atoms, amine groups, imine groups, ammonium groups,pyridine groups, pyridinium groups, ether groups, ester groups, amidegroups, carbonyl groups, thiocarbonyl groups, sulfate groups, sulfonategroups, sulfide groups, sulfoxide groups, phosphine groups, phosphoniumgroups, phosphate groups, mercapto groups, nitroso groups, sulfonegroups, acyl groups, acid anhydride groups, azide groups, and the like,wherein the substituents on the substituted alkyl groups, substitutedaryl groups, substituted arylalkyl groups, substituted alkoxy groups,substituted aryloxy groups, and substituted arylalkyloxy groups can be(but are not limited to) hydroxy groups, amine groups, imine groups,ammonium groups, pyridine groups, pyridinium groups, ether groups,aldehyde groups, ketone groups, ester groups, amide groups, carboxylicacid groups, carbonyl groups, thiocarbonyl groups, sulfate groups,sulfonate groups, sulfide groups, sulfoxide groups, phosphine groups,phosphonium groups, phosphate groups, cyano groups, nitrile groups,mercapto groups, nitroso groups, halogen atoms, nitro groups, sulfonegroups, acyl groups, acid anhydride groups, azide groups, mixturesthereof, and the like, wherein two or more substituents can be joinedtogether to form a ring.

While not being limited to any particular theory, it is believed thatthermal cure can also lead to extraction of the hydroxy group and tocrosslinking or chain extension at the “long” bond sites as shown below:

If desired, the hydroxyalkylated polymer can be further reacted with anunsaturated acid chloride to substitute some or all of the hydroxyalkylgroups with photosensitive groups such as acryloyl or methacryloylgroups or other unsaturated ester groups. The reaction can take place inthe presence of triethylamine, which acts as a hydrochloric acidscavenger to form NEt₃H⁺Cl⁻. Examples of suitable reactants includeacryloyl chloride, methacryloyl chloride, cinnamoyl chloride, crotonoylchloride, ethacryloyl chloride, oleyl chloride, linoleyl chloride,maleoyl chloride, fumaroyl chloride, itaconoyl chloride, citraconoylchloride, acid chlorides of phenylmaleic acid, 3-hexene-1,6-dicarboxylicacid, and the like. Examples of suitable solvents include1,1,2,2-tetrachloroethane, methylene chloride, and the like. Typically,the reactants are present in relative amounts with respect to each otherby weight of about 1 part hydroxyalkylated polymer, about 1 parttriethylamine, about 30 parts solvent, and about 1 part acid chloride.

Some or all of the hydroxyalkyl groups can be replaced with unsaturatedester substituents. Longer reaction times generally lead to greaterdegrees of substitution of hydroxyalkyl groups with unsaturated estersubstituents.

Typical reaction temperatures are from about 0 to about 50° C., andpreferably from about 10 to about 25° C., although the temperature canbe outside this range. Typical reaction times are from about 1 to about24 hours, and preferably from about 5 to about 16 hours, although thetime can be outside these ranges.

The general reaction scheme is as follows:

wherein a, b, c, d, e, f, g, h, i, j, k, and m are each integers of 0,1, 2, 3, or 4, provided that the sum of i+e is no greater than 4, thesum of j+f is no greater than 4, the sum of k+g is no greater than 4,and the sum of m+h is no greater than 4, provided that at least one ofa, b, c, and d is equal to or greater than 1 in at least some of themonomer repeat units of the polymer, and provided that at least one ofe, f, g, and h is equal to at least 1 in at least some of the monomerrepeat units of the polymer, and n is an integer representing the numberof repeating monomer units. In the corresponding reaction withmethacryloyl chloride, the

groups are replaced with

groups.

Higher degrees of hydroxyalkylation generally lead to higher degrees ofsubstitution with unsaturated ester groups and thereby to greaterphotosensitivity of the polymer. Different degrees of substitution maybe desirable for different applications. Too high a degree ofsubstitution may lead to excessive sensitivity, resulting incrosslinking or chain extension of both exposed and unexposed polymermaterial when the material is exposed imagewise to activating radiation,whereas too low a degree of substitution may be undesirable because ofresulting unnecessarily long exposure times or unnecessarily highexposure energies. For applications wherein the photopatternable polymeris to be used as a layer in a thermal ink jet printhead, the degree ofacryloylation (i.e., the average number of unsaturated ester groups permonomer repeat unit) preferably is from about 0.5 to about 1.2, and morepreferably from about 0.65 to about 0.8, although the degree ofsubstitution can be outside these ranges for ink jet printheadapplications. Optimum amounts of unsaturated ester substitution are fromabout 0.8 to about 1.3 milliequivalents of unsaturated ester group pergram of resin.

Some or all of the hydroxyalkyl groups can be replaced with unsaturatedester substituents. Longer reaction times generally lead to greaterdegrees of substitution of hydroxyalkyl groups with unsaturated estersubstituents.

While not being limited to any particular theory, it is believed thatexposure to, for example, ultraviolet radiation generally leads tocrosslinking or chain extension at the “long” bond sites as shown belowfor the specific example of polymers having acryloyl functional groups,wherein the ethylenic linkage in the acryloyl group is opened to formthe link:

Many of the photosensitivity-imparting groups which are indicated aboveas being capable of enabling crosslinking or chain extension of thepolymer upon exposure to actinic radiation can also enable crosslinkingor chain extension of the polymer upon exposure to elevatedtemperatures; thus the polymers of the present invention can also, ifdesired, be used in applications wherein thermal curing is employed.

In all of the above reactions and substitutions illustrated above forthe polymer of the formula

it is to be understood that analogous reactions and substitutions willoccur for the polymer of the formula

In another preferred embodiment of the present invention, a photoresistis prepared which comprises a mixture of the polymer substituted withphotoactive groups, such as hydroxyalkyl groups or unsaturated estergroups, and the halomethylated polymer. The halomethylated polymer,which can be used as an intermediate in the synthesis of thephotosensitivity-imparting group substituted polymer, also functions asan accelerator which generates free radicals upon exposure toultraviolet light, and thus can be used instead of or in addition toother accelerators or sensitizers, such as Michler's ketone or the like.In addition, the substitution of the halomethylated precursor with thephotosensitivity-imparting groups can be controlled so as to yield amixture containing a known proportion of the halomethyl residue.Accordingly, a photoresist can be prepared of thephotosensitivity-imparting group substituted polymer without the need toadd an additional initiator to the precursor material. Typically, thehalomethylated polymer (which typically is substituted to a degree offrom about 0.25 to about 2.0 halomethyl groups per monomer repeat unit,preferably from about 1 to about 2 halomethyl groups per monomer repeatunit, and more preferably from about 1.5 to about 2 halomethyl groupsper monomer repeat unit) and the photosensitivity-imparting groupsubstituted polymer (which typically is substituted to a degree of fromabout. 0.25 to about 2.0 photosensitivity-imparting groups per monomerrepeat unit, preferably from about 0.5 to about 1photosensitivity-imparting group per monomer repeat unit, and morepreferably from about 0.7 to about 0.8 photosensitivity-imparting groupper monomer repeat unit) are present in relative amounts such that thedegree of substitution when measured for the blended composition is fromabout 0.25 to about 1.5, preferably from about 0.5 to about 0.8, andmore preferably about 0.75 photosensitivity-imparting groups per monomerrepeat unit, and from about 0.25 to about 2.25, preferably from about0.75 to about 2, and more preferably from about 0.75 to about 1halomethyl group per monomer repeat unit, although the relative amountscan be outside these ranges. Similarly, a polymer substituted with bothhalomethyl and photosensitivity-imparting groups can function as anaccelerator. In this instance, the accelerating polymer typicallyexhibits a degree of substitution of from about 0.25 to about 1.5,preferably from about 0.5 to about 0.8, and more preferably about 0.75photosensitivity-imparting groups per monomer repeat unit, and fromabout 0.25 to about 2.25, preferably from about 0.75 to about 2, andmore preferably from about 0.75 to about 1 halomethyl group per monomerrepeat unit, although the relative amounts can be outside these ranges.

Particularly preferred as reaction accelerators are polymers of theformula

wherein A is selected so that the monomeric unit contains a benzophenonemoiety and x and B are as defined hereinabove, said polymer having atleast one halomethyl substituent per monomer repeat unit in at leastsome of the monomer repeat units of the polymer, said polymer having atleast one photosensitivity-imparting group per monomer repeat unit in atleast some of the monomer repeat units of the polymer. Examples ofsuitable A groups for this embodiment include

and the like. While not being limited to any particular theory, it isbelieved that in this embodiment, the presence of the benzophenonemoiety acts as a photoabsorbing element in the polymer backbone andcontributes to the photoinitiating characteristics of the polymer. Inthis embodiment, advantages include high sensitivity, highdevelopability, and high aspect ratios in thick films.

When the halomethylated polymer is present in relatively highconcentrations in a photoresist with respect to the amount ofphotosensitivity-imparting group substituted polymer, the halomethylatedmaterial can also act as an ultraviolet polymerization inhibitor.

The precise degree of photosensitivity-imparting group substitution ofthe polymer may be difficult to control, and different batches ofphotosensitivity-imparting group substituted polymers may have somewhatdifferent degrees of substitution even though the batches were preparedunder similar conditions. Photoresist compositions containing polymersfor which the degree of photosensitivity-imparting group substitutionvaries will exhibit variation in characteristics such as photospeed,imaging energy requirements, photosensitivity, shelf life, film formingcharacteristics, development characteristics, and the like. Accordingly,if desired, the photoresist composition can be formulated from a mixtureof (A) a first component comprising a polymer, at least some of themonomer repeat units of which have at least onephotosensitivity-imparting group thereon, said polymer having a firstdegree of photosensitivity-imparting group substitution measured inmilliequivalents of photosensitivity-imparting group per gram and beingof the above general formula; and (B) a second component which compriseseither (1) a polymer having a second degree ofphotosensitivity-imparting group substitution measured inmilliequivalents of photosensitivity-imparting group per gram lower thanthe first degree of photosensitivity-imparting group substitution,wherein said second degree of photosensitivity-imparting groupsubstitution may be zero, wherein the mixture of the first component andthe second component has a third degree of photosensitivity-impartinggroup substitution measured in milliequivalents ofphotosensitivity-imparting group per gram which is lower than the firstdegree of photosensitivity-imparting group substitution and higher thanthe second degree of photosensitivity-imparting group substitution, or(2) a reactive diluent having at least one photosensitivity-impartinggroup per molecule and having a fourth degree ofphotosensitivity-imparting group substitution measured inmilliequivalents of photosensitivity-imparting group per gram, whereinthe mixture of the first component and the second component has a fifthdegree of photosensitivity-imparting group substitution measured inmilliequivalents of photosensitivity-imparting group per gram which ishigher than the first degree of photosensitivity-imparting groupsubstitution and lower than the fourth degree ofphotosensitivity-imparting group substitution; wherein the weightaverage molecular weight of the mixture typically is from about 10,000to about 50,000, preferably from about 10,000 to about 35,000, and morepreferably from about 10,000 to about 25,000, although the weightaverage molecular weight of the blend can be outside these ranges; andwherein the third or fifth degree of photosensitivity-imparting groupsubstitution typically is from about 0.25 to about 2 milliequivalents ofphotosensitivity-imparting group per gram of mixture, preferably 0.8 toabout 1.4 milliequivalents of photosensitivity-imparting groups per gramof mixture, although the degree of substitution can be outside theseranges.

The first photosensitivity-imparting group substituted polymer can beprepared as described hereinabove. In one embodiment of the presentinvention, the second component is a polymer which either is substitutedwith photosensitivity-imparting groups but to a lesser degree than thefirst polymer, or which does not contain photosensitivity-impartinggroup substituents. The second polymer may be selected from a widevariety of polymers. For example, in one embodiment of the presentinvention, two different photosensitivity-imparting group substitutedpolymers are blended together, wherein one has a higher degree ofsubstitution than the other. In another embodiment of the presentinvention, the second polymer is a polymer of the above general formulabut having no photosensitivity-imparting group substituents, such as thepolymer starting materials (and, if deep ultraviolet, x-ray, or electronbeam radiation are not being used for photoexposure, the haloalkylatedpolymers prepared as described hereinabove). In yet another embodimentof the present invention, the second polymer is not necessarily apolymer of the above general formula, but is selected from any of a widevariety of other high performance polymers suitable for obtaining adesirable photoresist mixture with the desired characteristics, such asepoxies, polycarbonates, diallyl phthalates, chloromethylatedbis-fluorenones, polyphenylenes, phenoxy resins, polyarylene ethers,poly (ether imides), polyarylene ether ketones, polyphenylene sulfides,polysulfones, poly (ether sulfones), polyphenyl triazines, polyimides,polyphenyl quinoxalines, other polyheterocyclic systems, and the like,as well as mixtures thereof. High performance polymers typically aremoldable at temperatures above those at which their use is intended, andare useful for high temperature structural applications. While most highperformance polymers are thermoplastic, some, such as phenolics, tend tobe thermosetting. Any combination of photosensitivity-imparting groupsubstituted polymers of the above formula, polymers having nophotosensitivity-imparting group substituents but falling within theabove general formula, and/or other polymers outside the scope of theabove general formula can be used as the second polymer for the presentinvention. For example, in one embodiment of the present invention, aphotoresist is prepared from: (a) 60 parts by weight of a polyaryleneether ketone within the above general formula having 1 chloromethylgroup per repeating monomer unit, 1 acrylate group per repeating monomerunit, and a number average molecular weight of 60,000; (b) 40 parts byweight of a polyarylene ether ketone resin within the above generalformula but having no substituents thereon, with a number averagemolecular weight of 2,800 and a polydispersity (M_(w)/M_(n)) of about2.5; and (c) 10 parts by weight of EPON 1001 adhesive resin (ShellChemical Company, Houston, Tex.). This mixture has a degree ofacryloylation of about 1.1 milliequivalents of acrylate per gram ofresin solids and a weight average molecular weight of 34,000. Typically,when a photoresist is prepared from a mixture of an unsaturated estersubstituted polymer of the above general formula and a second polymerhaving no unsaturated ester groups, a photoresist solution containingabout 40 percent by weight polymer solids will contain from 10 to about25 parts by weight of a polymer having unsaturated ester substituentsand from about 10 to about 25 parts by weight of a polymer having nounsaturated ester substituents.

Alternatively, the second component can be a reactive diluent. In someembodiments, the reactive diluent is a liquid, and can replace a solventwhen the photopatternable polymer is too high in viscosity to be curedwithout solvents. In other embodiments, the reactive diluent is a solid.The reactive diluent has functional groups which are capable ofpolymerizing when the reactive diluent is exposed to actinic radiationat an energy or wavelength level which is capable of inducingcrosslinking or chain extension in the photopatternable polymer.Reactive diluents preferably are monomeric or oligomeric, and include(but are not limited to) mono-, di-, tri-, and multi-functionalunsaturated ester monomers and the like. Examples of suitable reactivediluents include monoacrylates, such as cyclohexyl acrylate, 2-ethoxyethyl acrylate, 2-methoxy ethyl acrylate, 2(2-ethoxyethoxy) ethylacrylate, stearyl acrylate, tetrahydrofurfuryl acrylate, octyl acrylate,lauryl acrylate, behenyl acrylate, 2-phenoxy ethyl acrylate, tertiarybutyl acrylate, glycidyl acrylate, isodecyl acrylate, benzyl acrylate,hexyl acrylate, isooctyl acrylate, isobornyl acrylate, butanediolmonoacrylate, ethoxylated phenol monoacrylate, oxyethylated phenolacrylate, monomethoxy hexanediol acrylate, β-carboxy ethyl acrylate,dicyclopentyl acrylate, carbonyl acrylate, octyl decyl acrylate,ethoxylated nonylphenol acrylate, hydroxyethyl acrylate, hydroxyethylmethacrylate, and the like, diacrylates, such as 1,3butylene glycoldiacrylate, 1,4-butanediol diacrylate, diethylene glycol diacrylate,1,6-hexanediol diacrylate, tetraethylene glycol diacrylate, triethyleneglycol diacrylate, tripropylene glycol diacrylate, polybutanedioldiacrylate, polyethylene glycol diacrylate, propoxylated neopentylglycol diacrylate, ethoxylated neopentyl glycol diacrylate,polybutadiene diacrylate, and the like, polyacrylates, such astrimethylol propane triacrylate, pentaerythritol tetraacrylate,pentaerythritol triacrylate, dipentaerythritol pentaacrylate, glycerolpropoxy triacrylate, tris(2-hydroxyethyl) isocyanurate triacrylate,pentaacrylate ester, and the like, epoxy acrylates, polyester acrylates,polyether polyol acrylates, urethane acrylates, amine acrylates, acrylicacrylates, and the like. Mixtures of two or more materials can also beemployed as the reactive diluent. Suitable reactive diluents arecommercially available from, for example, Sartomer Co., Inc., HenkelCorp., Radcure Specialties, and the like. When the second component is areactive diluent, typically, the first and second components are presentin relative amounts of from about 5 to about 50 percent by weightreactive diluent (second component) and from about 50 to about 95percent by weight polymer (first component), and preferably in relativeamounts of from about 10 to about 20 percent by weight reactive diluent(second component) and from about 80 to about 90 percent by weightpolymer (first component), although the relative amounts can be outsidethese ranges.

If desired, to reduce the amount of residual halogen in a photoresist orother composition containing the polymers of the present invention,thereby also reducing or eliminating the generation of hydrohalic acidduring a subsequent thermal curing step, any residual haloalkyl groupson the photopatternable polymer can be converted to methoxy groups,hydroxide groups, acetoxy groups, amine groups, or the like by anydesired process, including those processes disclosed hereinabove, thosedisclosed in, for example, British Patent 863,702, Chem Abstr. 55,18667b (1961), and other publications previously incorporated herein byreference, and the like.

Photopatternable polymers prepared by the process of the presentinvention can be used as components in ink jet printheads. Theprintheads of the present invention can be of any suitableconfiguration. An example of a suitable configuration, suitable in thisinstance for thermal ink jet printing, is illustrated schematically inFIG. 1, which depicts an enlarged, schematic isometric view of the frontface 29 of a printhead 10 showing the array of droplet emitting nozzles27. Referring also to FIG. 2, discussed later, the lower electricallyinsulating substrate or heating element plate 28 has the heatingelements 34 and addressing electrodes 33 patterned on surface 30thereof, while the upper substrate or channel plate 31 has parallelgrooves 20 which extend in one direction and penetrate through the uppersubstrate front face edge 29. The other end of grooves 20 terminate atslanted wall 21, the floor 41 of the internal recess 24 which is used asthe ink supply manifold for the capillary filled ink channels 20, has anopening 25 therethrough for use as an ink fill hole. The surface of thechannel plate with the grooves are aligned and bonded to the heaterplate 28, so that a respective one of the plurality of heating elements34 is positioned in each channel, formed by the grooves and the lowersubstrate or heater plate. Ink enters the manifold formed by the recess24 and the lower substrate 28 through the fill hole 25 and by capillaryaction, fills the channels 20 by flowing through an elongated recess 38formed in the thick film insulative layer 18. The ink at each nozzleforms a meniscus, the surface tension of which prevents the ink fromweeping therefrom. The addressing electrodes 33 on the lower substrateor channel plate 28 terminate at terminals 32. The upper substrate orchannel plate 31 is smaller than that of the lower substrate in orderthat the electrode terminals 32 are exposed and available for wirebonding to the electrodes on the daughter board 19, on which theprinthead 10 is permanently mounted. Layer 18 is a thick filmpassivation layer, discussed later, sandwiched between the upper andlower substrates. This layer is etched to expose the heating elements,thus placing them in a pit, and is etched to form the elongated recessto enable ink flow between the manifold 24 and the ink channels 20. Inaddition, the thick film insulative layer is etched to expose theelectrode terminals.

A cross sectional view of FIG. 1 is taken along view line 2—2 throughone channel and shown as FIG. 2 to show how the ink flows from themanifold 24 and around the end 21 of the groove 20 as depicted by arrow23. As is disclosed in U.S. Pat. Nos. 4,638,337, 4,601,777, and U.S.Pat. No. Re. 32,572, the disclosures of each of which are totallyincorporated herein by reference, a plurality of sets of bubblegenerating heating elements 34 and their addressing electrodes 33 can bepatterned on the polished surface of a single side polished (100)silicon wafer. Prior to patterning, the multiple sets of printheadelectrodes 33, the resistive material that serves as the heatingelements 34, and the common return 35, the polished surface of the waferis coated with an underglaze layer 39 such as silicon dioxide, having atypical thickness of from about 5,000 Angstroms to about 2 microns,although the thickness can be outside this range. The resistive materialcan be a doped polycrystalline silicon, which can be deposited bychemical vapor deposition (CVD) or any other well known resistivematerial such as zirconium boride (ZrB₂). The common return and theaddressing electrodes are typically aluminum leads deposited on theunderglaze and over the edges of the heating elements. The common returnends or terminals 37 and addressing electrode terminals 32 arepositioned at predetermined locations to allow clearance for wirebonding to the electrodes (not shown) of the daughter board 19, afterthe channel plate 31 is attached to make a printhead. The common return35 and the addressing electrodes 33 are deposited to a thicknesstypically of from about 0.5 to about 3 microns, although the thicknesscan be outside this range, with the preferred thickness being 1.5microns.

If polysilicon heating elements are used, they may be subsequentlyoxidized in steam or oxygen at a relatively high temperature, typicallyabout 1,100° C. although the temperature can be above or below thisvalue, for a period of time typically of from about 50 to about 80minutes, although the time period can be outside this range, prior tothe deposition of the aluminum leads, in order to convert a smallportion of the polysilicon to SiO₂. In such cases, the heating elementsare thermally oxidized to achieve an overglaze (not shown) of SiO₂ witha thickness typically of from about 500 Angstroms to about 1 micron,although the thickness can be outside this range, which has goodintegrity with substantially no pinholes.

In one embodiment, polysilicon heating elements are used and an optionalsilicon dioxide thermal oxide layer 17 is grown from the polysilicon inhigh temperature steam. The thermal oxide layer is typically grown to athickness of from about 0.5 to about 1 micron, although the thicknesscan be outside this range, to protect and insulate the heating elementsfrom the conductive ink. The thermal oxide is removed at the edges ofthe polysilicon heating elements for attachment of the addressingelectrodes and common return, which are then patterned and deposited. Ifa resistive material such as zirconium boride is used for the heatingelements, then other suitable well known insulative materials can beused for the protective layer thereover. Before electrode passivation, atantalum (Ta) layer (not shown) can be optionally deposited, typicallyto a thickness of about 1 micron, although the thickness can be above orbelow this value, on the heating element protective layer 17 for addedprotection thereof against the cavitational forces generated by thecollapsing ink vapor bubbles during printhead operation. The tantalumlayer is etched off all but the protective layer 17 directly over theheating elements using, for example, CF₄/O₂ plasma etching. Forpolysilicon heating elements, the aluminum common return and addressingelectrodes typically are deposited on the underglaze layer and over theopposing edges of the polysilicon heating elements which have beencleared of oxide for the attachment of the common return and electrodes.

For electrode passivation, a film 16 is deposited over the entire wafersurface, including the plurality of sets of heating elements andaddressing electrodes. The passivation film 16 provides an ion barrierwhich will protect the exposed electrodes from the ink. Examples ofsuitable ion barrier materials for passivation film 16 includepolyimide, plasma nitride, phosphorous doped silicon dioxide, materialsdisclosed herein as being suitable for insulative layer 18, and thelike, as well as any combinations thereof. An effective ion barrierlayer is generally achieved when its thickness is from about 1000Angstroms to about 10 microns, although the thickness can be outsidethis range. In 300 dpi printheads, passivation layer 16 preferably has athickness of about 3 microns, although the thickness can be above orbelow this value. In 600 dpi printheads, the thickness of passivationlayer 16 preferably is such that the combined thickness of layer 16 andlayer 18 is about 25 microns, although the thickness can be above orbelow this value. The passivation film or layer 16 is etched off of theterminal ends of the common return and addressing electrodes for wirebonding later with the daughter board electrodes. This etching of thesilicon dioxide film can be by either the wet or dry etching method.Alternatively, the electrode passivation can be by plasma depositedsilicon nitride (Si₃N₄).

Next, a thick film type insulative layer 18, of a polymeric materialdiscussed in further detail herein, is formed on the passivation layer16, typically having a thickness of from about 10 to about 100 micronsand preferably in the range of from about 25 to about 50 microns,although the thickness can be outside these ranges. Even morepreferably, in 300 dpi printheads, layer 18 preferably has a thicknessof about 30 microns, and in 600 dpi printheads, layer 18 preferably hasa thickness of from about 20 to about 22 microns, although otherthicknesses can be employed. The insulative layer 18 isphotolithographically processed to enable etching and removal of thoseportions of the layer 18 over each heating element (forming recesses26), the elongated recess 38 for providing ink passage from the manifold24 to the ink channels 20, and over each electrode terminal 32, 37. Theelongated recess 38 is formed by the removal of this portion of thethick film layer 18. Thus, the passivation layer 16 alone protects theelectrodes 33 from exposure to the ink in this elongated recess 38.Optionally, if desired, insulative layer 18 can be applied as a seriesof thin layers of either similar or different composition. Typically, athin layer is deposited, photoexposed, partially cured, followed bydeposition of the next thin layer, photoexposure, partial curing, andthe like. The thin layers constituting thick film insulative layer 18contain a polymer of the formula indicated hereinabove. In oneembodiment of the present invention, a first thin layer is applied tocontact layer 16, said first thin layer containing a mixture of apolymer of the formula indicated hereinabove and an epoxy polymer,followed by photoexposure, partial curing, and subsequent application ofone or more successive thin layers containing a polymer of the formulaindicated hereinabove.

FIG. 3 is a similar view to that of FIG. 2 with a shallowanisotropically etched groove 40 in the heater plate, which is silicon,prior to formation of the underglaze 39 and patterning of the heatingelements 34, electrodes 33 and common return 35. This recess 40 permitsthe use of only the thick film insulative layer 18 and eliminates theneed for the usual electrode passivating layer 16. Since the thick filmlayer 18 is impervious to water and relatively thick (typically fromabout 20 to about 40 microns, although the thickness can be outside thisrange), contamination introduced into the circuitry will be much lessthan with only the relatively thin passivation layer 16 well known inthe art. The heater plate is a fairly hostile environment for integratedcircuits. Commercial ink generally entails a low attention to purity. Asa result, the active part of the heater plate will be at elevatedtemperature adjacent to a contaminated aqueous ink solution whichundoubtedly abounds with mobile ions. In addition, it is generallydesirable to run the heater plate at a voltage of from about 30 to about50 volts, so that there will be a substantial field present. Thus, thethick film insulative layer 18 provides improved protection for theactive devices and provides improved protection, resulting in longeroperating lifetime for the heater plate.

When a plurality of lower substrates 28 are produced from a singlesilicon wafer, at a convenient point after the underglaze is deposited,at least two alignment markings (not shown) preferably arephotolithographically produced at predetermined locations on the lowersubstrates 28 which make up the silicon wafer. These alignment markingsare used for alignment of the plurality of upper substrates 31containing the ink channels. The surface of the single sided wafercontaining the plurality of sets of heating elements is bonded to thesurface of the wafer containing the plurality of ink channel containingupper substrates subsequent to alignment.

As disclosed in U.S. Pat. Nos. 4,601,777 and 4,638,337, the disclosuresof each of which are totally incorporated herein by reference, thechannel plate is formed from a two side polished, (100) silicon wafer toproduce a plurality of upper substrates 31 for the printhead. After thewafer is chemically cleaned, a pyrolytic CVD silicon nitride layer (notshown) is deposited on both sides. Using conventional photolithography,a via for fill hole 25 for each of the plurality of channel plates 31and at least two vias for alignment openings (not shown) atpredetermined locations are printed on one wafer side. The siliconnitride is plasma etched off of the patterned vias representing the fillholes and alignment openings. A potassium hydroxide (KOH) anisotropicetch can be used to etch the fill holes and alignment openings. In thiscase, the [111] planes of the (100) wafer typically make an angle ofabout 54.7 degrees with the surface of the wafer. The fill holes aresmall square surface patterns, generally of about 20 mils (500 microns)per side, although the dimensions can be above or below this value, andthe alignment openings are from about 60 to about 80 mils (1.5 to 3millimeters) square, although the dimensions can be outside this range.Thus, the alignment openings are etched entirely through the 20 mil (0.5millimeter) thick wafer, while the fill holes are etched to aterminating apex at about halfway through to three-quarters through thewafer. The relatively small square fill hole is invariant to furthersize increase with continued etching so that the etching of thealignment openings and fill holes are not significantly timeconstrained.

Next, the opposite side of the wafer is photolithographically patterned,using the previously etched alignment holes as a reference to form therelatively large rectangular recesses 24 and sets of elongated, parallelchannel recesses that will eventually become the ink manifolds andchannels of the printheads. The surface 22 of the wafer containing themanifold and channel recesses are portions of the original wafer surface(covered by a silicon nitride layer) on which an adhesive, such as athermosetting epoxy, will be applied later for bonding it to thesubstrate containing the plurality of sets of heating elements. Theadhesive is applied in a manner such that it does not run or spread intothe grooves or other recesses. The alignment markings can be used with,for example, a vacuum chuck mask aligner to align the channel wafer onthe heating element and addressing electrode wafer. The two wafers areaccurately mated and can be tacked together by partial curing of theadhesive. Alternatively, the heating element and channel wafers can begiven precisely diced edges and then manually or automatically alignedin a precision jig. Alignment can also be performed with an infraredaligner-bonder, with an infrared microscope using infrared opaquemarkings on each wafer to be aligned, or the like. The two wafers canthen be cured in an oven or laminator to bond them together permanently.The channel wafer can then be milled to produce individual uppersubstrates. A final dicing cut, which produces end face 29, opens oneend of the elongated groove 20 producing nozzles 27. The other ends ofthe channel groove 20 remain closed by end 21. However, the alignmentand bonding of the channel plate to the heater plate places the ends 21of channels 20 directly over elongated recess 38 in the thick filminsulative layer 18 as shown in FIG. 2 or directly above the recess 40as shown in FIG. 3 enabling the flow of ink into the channels from themanifold as depicted by arrows 23. The plurality of individualprintheads produced by the final dicing are bonded to the daughter boardand the printhead electrode terminals are wire bonded to the daughterboard electrodes.

In one embodiment, a heater wafer with a phosphosilicate glass layer isspin coated with a solution of Z6020 adhesion promoter (0.01 weightpercent in 95 parts methanol and 5 parts water, Dow Corning) at 3000revolutions per minute for 10 seconds and dried at 100° C. for between 2and 10 minutes. The wafer is then allowed to cool at 25° C. for 5minutes before spin coating the photoresist containing thephotopatternable polymer onto the wafer at between 1,000 and 3,000revolutions per minute for between 30 and 60 seconds. The photoresistsolution is made by dissolving polyarylene ether ketone with 0.75acryloyl groups and 0.75 hydroxymethyl groups per repeat unit and aweight average molecular weight of 25,000 in N-methylpyrrolidinone at 40weight percent solids with Michler's ketone (1.2 parts ketone per every10 parts of 40 weight percent solids polymer solution). The film isheated (soft baked) in an oven for between 10 and 15 minutes at 70° C.After cooling to 25° C. over 5 minutes, the film is covered with a maskand exposed to 365 nanometer ultraviolet light, amounting to between 150and 1,500 millijoules per cm². The exposed wafer is then heated at 70°C. for 2 minutes post exposure bake, followed by cooling to 25° C. over5 minutes. The film is developed with 60:40 chloroform/cyclohexanonedeveloper, washed with 90:10 hexanes/cyclohexanone, and then dried at70° C. for 2 minutes. A second developer/wash cycle is carried out ifnecessary to obtain a wafer with clean features. The processed wafer istransferred to an oven at 25° C., and the oven temperature is raisedfrom 25 to 90° C. at 2° C. per minute. The temperature is maintained at90° C. for 2 hours, and then increased to 260° C. at 2° C. per minute.The oven temperature is maintained at 260° C. for 2 hours and then theoven is turned off and the temperature is allowed to cool gradually to25° C. When thermal cure of the photoresist films is carried out underinert atmosphere, such as nitrogen or one of the noble gases, such asargon, neon, krypton, xenon, or the like, there is markedly reducedoxidation of the developed film and improved thermal and hydrolyticstability of the resultant devices. Moreover, adhesion of developedphotoresist film is improved to the underlying substrate. If a secondlayer is spin coated over the first layer, the heat cure of the firstdeveloped layer can be stopped between 80 and 260° C. before the secondlayer is spin coated onto the first layer. A second thicker layer isdeposited by repeating the above procedure a second time. This processis intended to be a guide in that procedures can be outside thespecified conditions depending on film thickness and photoresistmolecular weight. Films at 30 microns have been developed with cleanfeatures at 600 dots per inch.

For best results with respect to well-resolved features and high aspectratios, photoresist compositions of the present invention are free ofparticulates prior to coating onto substrates. In one preferredembodiment, the photoresist composition containing the photopatternablepolymer is subjected to filtration through a 2 micron nylon filter cloth(available from Tetko). The photoresist solution is filtered through thecloth under yellow light or in the dark as a solution containing fromabout 30 to about 60 percent by weight solids using compressed air (upto about 60 psi) and a pressure filtration funnel. No dilution of thephotoresist solution is required, and concentrations of an inhibitor(such as, for example, MEHQ) can be as low as, for example, 500 partsper million or less by weight without affecting shelf life. No build inmolecular weight of the photopatternable polymer is observed during thisfiltration process. While not being limited to any particular theory, itis believed that in some instances, such as those when unsaturated estergroups are present on the photopolymerizable polymer, compressed airyields results superior to those obtainable with inert atmospherebecause oxygen in the compressed air acts as an effective inhibitor forthe free radical polymerization of unsaturated ester groups such asacrylates and methacrylates.

In a particularly preferred embodiment, the photopatternable polymer isadmixed with an epoxy resin in relative amounts of from about 75 partsby weight photopatternable polymer and about 25 parts by weight epoxyresin to about 90 parts by weight photopatternable polymer and about 10parts by weight epoxy resin. Examples of suitable epoxy resins includeEPON 1001F, available from Shell Chemical Company, Houston, Tex.,believed to be of the formula

and the like, as well as mixtures thereof. Curing agents such as the “Y”curative (meta-phenylenediamine) and the like, as well as mixturesthereof, can be used to cure the epoxy resin at typical relative amountsof about 10 weight percent curative per gram of epoxy resin solids.Process conditions for the epoxy resin blended with the photopatternablepolymer are generally similar to those used to process the photoresistwithout epoxy resin. Preferably, the epoxy or epoxy blend is selected sothat its curing conditions are different from the conditions employed toapply, image, develop, and cure the photopatternable polymer. Selectivestepwise curing allows development of the photoresist film before curingthe epoxy resin to prevent unwanted epoxy residues on the device.Incorporation of the epoxy resin into the photopatternable polymermaterial improves the adhesion of the photopatternable layer to theheater plate. Subsequent to imaging and during cure of thephotopatternable polymer, the epoxy reacts with the heater layer to formstrong chemical bonds with that layer, improving adhesive strength andsolvent resistance of the interface. The presence of the epoxy may alsoimprove the hydrophilicity of the photopatternable polymer and thus mayimprove the wetting properties of the layer, thereby improving therefill characteristics of the printhead.

The printhead illustrated in FIGS. 1 through 3 constitutes a specificembodiment of the present invention. Any other suitable printheadconfiguration comprising ink-bearing channels terminating in nozzles onthe printhead surface can also be employed with the materials disclosedherein to form a printhead of the present invention.

The present invention also encompasses printing processes withprintheads according to the present invention. One embodiment of thepresent invention is directed to an ink jet printing process whichcomprises (1) preparing an ink jet printhead comprising a plurality ofchannels, wherein the channels are capable of being filled with ink froman ink supply and wherein the channels terminate in nozzles on onesurface of the printhead, said preparation being according to theprocess of the present invention; (2) filling the channels with an ink;and (3) causing droplets of ink to be expelled from the nozzles onto areceiver sheet in an image pattern. A specific embodiment of thisprocess is directed to a thermal ink jet printing process, wherein thedroplets of ink are caused to be expelled from the nozzles by heatingselected channels in an image pattern. The droplets can be expelled ontoany suitable receiver sheet, such as fabric, plain paper such as Xerox®4024 or 4010, coated papers, transparency materials, or the like.

Specific embodiments of the invention will now be described in detail.These examples are intended to be illustrative, and the invention is notlimited to the materials, conditions, or process parameters set forth inthese embodiments. All parts and percentages are by weight unlessotherwise indicated.

EXAMPLE I

A polyarylene ether ketone of the formula

wherein n is between about 2 and about 30 (hereinafter referred to aspoly(4-CPK-BPA)) was prepared as follows. A 5-liter, 3-neck round-bottomflask equipped with a Dean-Stark (Barrett) trap, condenser, mechanicalstirrer, argon inlet, and stopper was situated in a silicone oil bath.4,4′-Dichlorobenzophenone (Aldrich 11,370, Aldrich Chemical Co.,Milwaukee, Wis., 250 grams), bis-phenol A (Aldrich 23,965-8, 244.8grams), potassium carbonate (327.8 grams), anhydrousN,N-dimethylacetamide (1,500 milliliters), and toluene (275 milliliters)were added to the flask and heated to 175° C. (oil bath temperature)while the volatile toluene component was collected and removed. Afterhours of heating 30 hours at 175° C. with continuous stirring, thereaction mixture was filtered to remove insoluble salts, and theresultant solution was added to methanol (5 gallons) to precipitate thepolymer. The polymer was isolated by filtration, and the wet filter cakewas washed with water (3 gallons) and then with methanol (3 gallons).The yield was 360 grams of vacuum dried polymer. The molecular weight ofthe polymer was determined by gel permeation chromatography (gpc)(elution solvent was tetrahydrofuran) with the following results: M_(n)2,800, M_(peak) 5,800, M_(w) 6,500, M_(z) 12,000 and M_(z+1) 17,700. Asa result of the stoichiometries used in the reaction, it is believedthat this polymer had end groups derived from bis-phenol A. When thereaction was allowed to proceed for 35, 40, and 48 hours at 175° C., therespective values of M_(n) of the poly(4-CPK-BPA) formed were 3,000,3,300, and 4,000.

A solution containing 100 parts by weight of the polyarylene etherketone thus prepared having a M_(n) of 2,800, 44.5 parts by weight ofparaformaldehyde, 1 part by weight sodium hydroxide, and 1 part byweight tetramethylammonium hydroxide in 200 parts by weight1,1,2,2-tetrachloroethane was heated at 100° C. Vigorous stirring andheating were continued for 16 hours. The resultant mixture was extractedwith water and the organic layer was dried over magnesium sulfate. Afterprecipitation into methanol, the filtered polymer was vacuum dried toyield 100 parts by weight hydroxymethylated polyarylene ether ketonewith 1.0 hydroxymethyl group per repeat unit.

Thereafter, 1 part by weight of the hydroxymethylated polymer thusformed was allowed to react with 1 part by weight of isocyanatoethylmethacrylate in 20 parts by weight methylene chloride to form anacryloylated and hydroxymethylated polymer at 25° C. within 16 hours.The resultant polymer had about 0.7 acryloyl groups per repeat unit.

EXAMPLE II

A hydroxymethylated polyarylene ether ketone was prepared as describedin Example I. One part by weight of the hydroxymethylated polymer wasallowed to react with 1 part by weight of acryloyl chloride in 30 partsby weight methylene chloride in the presence of 1 part by weighttriethylamine. The reaction mixture was cooled in an ice bath, and theice bath was allowed to melt while the reaction mixture was stirred at25° C. for 16 hours. The resultant polymer had 0.6 acryloyl groups perrepeat unit.

EXAMPLE III

A polyarylene ether ketone of the formula

wherein n is between about 2 and about 30 (hereinafter referred to aspoly(4-CPK-BPA)) was prepared as follows. A 5 liter, 3-neck round-bottomflask equipped with a Dean-Stark (Barrett) trap, condenser, mechanicalstirrer, argon inlet, and stopper was situated in a silicone oil both.4,4′-Dichlorobenzophenone (Aldrich 11,370, Aldrich Chemical Co.,Milwaukee, Wis., 250 grams), bis-phenol A (Aldrich 23,965-8, 244.8grams), potassium carbonate (327.8 grams), anhydrousN,N-dimethylacetamide (1,500 milliliters), and toluene (275 milliliters)were added to the flask and heated to 175° C. (oil bath temperature)while the volatile toluene component was collected and removed. After 48hours of heating at 175° C. with continuous stirring, the reactionmixture was filtered to remove insoluble salts, and the resultantsolution was added to methanol (5 gallons) to precipitate the polymer.The polymer was isolated by filtration, and the wet filter cake waswashed with water (3 gallons) and then with methanol (3 gallons). Theyield was 360 grams of vacuum dried polymer. The molecular weight of thepolymer was determined by gel permeation chromatography (gpc) (elutionsolvent was tetrahydrofuran) with the following results: M_(n) 3,430,M_(peak) 5,380, M_(w) 3,600, M_(z) 8,700, and M_(z+1) 12,950. The glasstransition temperature of the polymer was between 125 and 155° C. asdetermined using differential scanning calorimetry at a heating rate of20° C. per minute dependent on molecular weight. Solution cast filmsfrom methylene chloride were clear, tough, and flexible. As a result ofthe stoichiometries used in the reaction, it is believed that thispolymer had end groups derived from bis-phenol A.

A solution of chloromethyl ether in methyl acetate was made by adding282.68 grams (256 milliliters) of acetyl chloride to a mixture ofdimethoxy methane (313.6 grams, 366.8 milliliters) and methanol (10milliliters) in a 5 liter 3-neck round-bottom flask equipped with amechanical stirrer, argon inlet, reflux condenser, and addition funnel.The solution was diluted with 1,066.8 milliliters of1,1,2,2-tetrachloroethane and then tin tetrachloride (2.4 milliliters)was added via a gas-tight syringe, along with 1,1,2,2-tetrachloroethane(133.2 milliliters) using an addition funnel. The reaction solution washeated to 50° C. and a solution of poly(4-CPK-BPA) (160.8 grams) in1,1,2,2-tetrachloroethane (1,000 milliliters) was rapidly added. Thereaction mixture was then heated to reflux with an oil bath set at 110°C. After four hours reflux with continuous stirring, heating wasdiscontinued and the mixture was allowed to cool to 25° C. The reactionmixture was transferred in stages to a 2 liter round bottom flask andconcentrated using a rotary evaporator with gentle heating up to 50° C.and reduced pressure maintained with a vacuum pump trapped with liquidnitrogen. The concentrate was added to methanol (6 gallons) toprecipitate the polymer using a Waring blender. The polymer was isolatedby filtration and vacuum dried to yield 200 grams of poly(4-CPK-BPA)with 1.5 chloromethyl groups per repeat unit as identified using ¹H NMRspectrometry.

A solution containing 13.8 parts by weight of the chloromethylatedpolymer, 23 parts by weight tetrabutylammonium hydroxide, 7.6 partswater, and 50 parts by weight methylene chloride is stirred at 25° C.while 30 parts by weight of an aqueous sodium hydroxide solution (50percent by weight sodium hydroxide) is added. Stirring at 25° C. iscontinued for 16 hours, at which time the organic layer is separated,washed with water, dried over magnesium sulfate, and added to methanol(1 gallon) using a Waring blender to precipitate the polymer. Thefiltered polymer is vacuum dried to obtain about 12 parts by weight ofthe hydroxymethylated polymer containing 1 hydroxymethyl group perrepeat unit. Refluxing the reaction mixture results in nearly totalreplacement of the chloromethyl groups by the hydroxymethyl groups.

The hydroxymethylated polymer is then reacted with acryloyl chloride andisocyanatoethyl methacrylate as described in Example I.

EXAMPLE IV

A polyarylene ether ketone of the formula

wherein n is between about 6 and about 30 (hereinafter referred to aspoly(4-CPK-BPA)) was prepared as follows. A 1 liter, 3-neck round-bottomflask equipped with a Dean-Stark (Barrett) trap, condenser, mechanicalstirrer, argon inlet, and stopper was situated in a silicone oil bath.4,4′-Dichlorobenzophenone (Aldrich 11,370, Aldrich Chemical Co.,Milwaukee, Wis., 53.90 grams), bis-phenol A (Aldrich 23,965-8, 45.42grams), potassium carbonate (65.56 grams), anhydrousN,N-dimethylacetamide (300 milliliters), and toluene (55 milliliters)were added to the flask and heated to 175° C. (oil bath temperature)while the volatile toluene component was collected and removed. After 24hours of heating at 175° C. with continuous stirring, the reactionmixture was filtered to remove potassium carbonate and precipitated intomethanol (2 gallons). The polymer (poly(4-CPK-BPA)) was isolated in 86%yield after filtration and drying in vacuo. GPC analysis was as follows:M_(n) 4,239, M_(peak) 9,164, M_(w) 10,238, M_(z) 18,195, and M_(z+1)25,916. Solution cast films from methylene chloride were clear, tough,and flexible. As a result of the stoichiometries used in the reaction,it is believed that this polymer had end groups derived from4,4-dichlorobenzophenone.

EXAMPLE V

A polymer of the formula

wherein n represents the number of repeating monomer units was preparedas follows. A 500 milliliter, 3-neck round-bottom flask equipped with aDean-Stark (Barrett) trap, condenser, mechanical stirrer, argon inlet,and stopper was situated in a silicone oil bath.4,4′-Dichlorobenzophenone (Aldrich 11,370, Aldrich Chemical Co.,Milwaukee, Wis., 16.32 grams, 0.065 mol), bis(4-hydroxyphenyl)methane(Aldrich, 14.02 grams, 0.07 mol), potassium carbonate (21.41 grams),anhydrous N,N-dimethylacetamide (100 milliliters), and toluene (100milliliters) were added to the flask and heated to 175° C. (oil bathtemperature) while the volatile toluene component was collected andremoved. After 48 hours of heating at 175° C. with continuous stirring,the reaction mixture was filtered and added to methanol to precipitatethe polymer, which was collected by filtration, washed with water, andthen washed with methanol. The yield of vacuum dried product,poly(4-CPK-BPM), was 24 grams. The polymer dissolved on heating inN-methylpyrrolidinone, N,N-dimethylacetamide, and1,1,2,2-tetrachloroethane. The polymer remained soluble after thesolution had cooled to 25° C.

EXAMPLE VI

The polymer poly(4-CPK-BPM), prepared as described in Example V, waschloromethylated as follows. A solution of chloromethyl methyl ether (6mmol/milliliter) in methyl acetate was prepared by adding acetylchloride (35.3 grams) to a mixture of dimethoxymethane (45 milliliters)and methanol (1.25 milliliters). The solution was diluted with 150milliliters of 1,1,2,2-tetrachloroethane and then tin tetrachloride (0.3milliliters) was added. After taking the mixture to reflux using an oilbath set at 110° C., a solution of poly(4-CPK-BPM) (10 grams) in 125milliliters of 1,1,2,2-tetrachloroethane was added. Reflux wasmaintained for 2 hours and then 5 milliliters of methanol were added toquench the reaction. The reaction solution was added to 1 gallon ofmethanol using a Waring blender to precipitate the product,chloromethylated poly(4-CPK-BPM), which was collected by filtration andvacuum dried. The yield was 9.46 grams of poly(4-CPK-BPM) with 2chloromethyl groups per polymer repeat unit. The polymer had thefollowing structure:

EXAMPLE VII

A polymer of the formula

wherein n represents the number of repeating monomer units was preparedas follows. A 500 milliliter, 3-neck round-bottom flask equipped with aDean-Stark (Barrett) trap, condenser, mechanical stirrer, argon inlet,and stopper was situated in a silicone oil bath.4,4′-Dichlorobenzophenone (Aldrich 11,370, Aldrich Chemical Co.,Milwaukee, Wis., 16.32 grams, 0.065 mol), hexafluorobisphenol A(Aldrich, 23.52 grams, 0.07 mol), potassium carbonate (21.41 grams),anhydrous N,N-dimethylacetamide (100 milliliters), and toluene (100milliliters) were added to the flask and heated to 175° C. (oil bathtemperature) while the volatile toluene component was collected andremoved. After 48 hours of heating at 175° C. with continuous stirring,the reaction mixture was filtered and added to methanol to precipitatethe polymer, which was collected by filtration, washed with water, andthen washed with methanol. The yield of vacuum dried product,poly(4-CPK-HFBPA), was 20 grams. The polymer was analyzed by gelpermeation chromatography (gpc) (elution solvent was tetrahydrofuran)with the following results: M_(n) 1,975, M_(peak) 2,281, M_(w) 3,588,and M_(z+1) 8,918.

EXAMPLE VIII

The polymer poly(4-CPK-HFBPA), prepared as described in Example VII, ischloromethylated by the process described in Example VI. It is believedthat similar results will be obtained.

EXAMPLE IX

A polymer of the formula

wherein n represents the number of repeating monomer units was preparedas follows. A 1-liter, 3-neck round-bottom flask equipped with aDean-Stark (Barrett) trap, condenser, mechanical stirrer, argon inlet,and stopper was situated in a silicone oil bath.4,4′-Difluorobenzophenone (Aldrich Chemical Co., Milwaukee, Wis., 43.47grams, 0.1992 mol), 9,9′-bis(4-hydroxyphenyl)fluorenone (Ken Seika,Rumson, N.J., 75.06 grams, 0.2145 mol), potassium carbonate (65.56grams), anhydrous N,N-dimethylacetamide (300 milliliters), and toluene(52 milliliters) were added to the flask and heated to 175° C. (oil bathtemperature) while the volatile toluene component was collected andremoved. After 5 hours of heating at 175° C. with continuous stirring,the reaction mixture was allowed to cool to 25° C. The solidified masswas treated with acetic acid (vinegar) and extracted with methylenechloride, filtered, and added to methanol to precipitate the polymer,which was collected by filtration, washed with water, and then washedwith methanol. The yield of vacuum dried product, poly(4-FPK-FBPA), was71.7 grams. The polymer was analyzed by gel permeation chromatography(gpc) (elution solvent was tetrahydrofuran) with the following results:M_(n) 59,100, M_(peak) 144,000, M_(w) 136,100, M_(z) 211,350, andM_(z+1) 286,100.

EXAMPLE X

A polymer of the formula

wherein n represents the number of repeating monomer units was preparedas follows. A 1-liter, 3-neck round-bottom flask equipped with aDean-Stark (Barrett) trap, condenser, mechanical stirrer, argon inlet,and stopper was situated in a silicone oil bath.4,4′-Dichlorobenzophenone (Aldrich Chemical Co., Milwaukee, Wis., 50.02grams, 0.1992 mol), 9,9′-bis(4-hydroxyphenyl)fluorenone (Ken Seika,Rumson, N.J., 75.04 grams, 0.2145 mol), potassium carbonate (65.56grams), anhydrous N,N-dimethylacetamide (300 milliliters), and toluene(52 milliliters) were added to the flask and heated to 175° C. (oil bathtemperature) while the volatile toluene component was collected andremoved. After 24 hours of heating at 175° C. with continuous stirring,the reaction mixture was allowed to cool to 25° C. The reaction mixturewas filtered and added to methanol to precipitate the polymer, which wascollected by filtration, washed with water, and then washed withmethanol. The yield of vacuum dried product, poly(4-CPK-FBP), was 60grams.

EXAMPLE XI

The polymer poly(4-CPK-FBP), prepared as described in Example X, waschloromethylated as follows. A solution of chloromethyl methyl ether (6mmol/milliliter) in methyl acetate was prepared by adding acetylchloride (38.8 grams) to a mixture of dimethoxymethane (45 milliliters)and methanol (1.25 milliliters). The solution was diluted with 100milliliters of 1,1,2,2-tetrachloroethane and then tin tetrachloride (0.5milliliters) was added in 50 milliliters of 1,1,2,2-tetrachloroethane.After taking the mixture to reflux using an oil bath set at 100° C., asolution of poly(4-CPK-FBP) (10 grams) in 125 milliliters of1,1,2,2-tetrachloroethane was added. The reaction temperature wasmaintained at 100° C. for 1 hour and then 5 milliliters of methanol wereadded to quench the reaction. The reaction solution was added to 1gallon of methanol using a Waring blender to precipitate the product,chloromethylated poly(4-CPK-FBP), which was collected by filtration andvacuum dried. The yield was 9.5 grams of poly(4-CPK-FBP) with 1.5chloromethyl groups per polymer repeat unit. When the reaction wascarried out at 110° C. (oil bath set temperature), the polymer gelledwithin 80 minutes. The polymer had the following structure:

EXAMPLE XII

A polymer of the formula

wherein n represents the number of repeating monomer units was preparedas follows. A 1-liter, 3-neck round-bottom flask equipped with aDean-Stark (Barrett) trap, condenser, mechanical stirrer, argon inlet,and stopper was situated in a silicone oil bath.4,4′-Difluorobenzophenone (Aldrich Chemical Co., Milwaukee, Wis., 16.59grams), bisphenol A (Aldrich 14.18 grams, 0.065 mol), potassiumcarbonate (21.6 grams), anhydrous N,N-dimethylacetamide (100milliliters), and toluene (30 milliliters) were added to the flask andheated to 175° C. (oil bath temperature) while the volatile toluenecomponent was collected and removed. After 4 hours of heating at 175° C.with continuous stirring, the reaction mixture was allowed to cool to25° C. The solidified mass was treated with acetic acid (vinegar) andextracted with methylene chloride, filtered, and added to methanol toprecipitate the polymer, which was collected by filtration, washed withwater, and then washed with methanol. The yield of vacuum dried product,poly(4-FPK-BPA), was 12.22 grams. The polymer was analyzed by gelpermeation chromatography (gpc) (elution solvent was tetrahydrofuran)with the following results: M_(n) 5,158, M_(peak) 15,080, M_(w) 17,260,and M_(z+1) 39,287. To obtain a lower molecular weight, the reaction canbe repeated with a 15 mol % offset in stoichiometry.

EXAMPLE XIII

4′-Methylbenzoyl-2,4-dichlorobenzene, of the formula

was prepared as follows. To a 2-liter flask equipped with a mechanicalstirrer, argon inlet, Dean Stark trap, condenser, and stopper andsituated in an oil bath was added toluene (152 grams). The oil bathtemperature was raised to 130° C. and 12.5 grams of toluene wereremoved. There was no indication of water. The flask was removed fromthe oil bath and allowed to cool to 25° C. 2,4-Dichlorobenzoyl chloride(0.683 mol, 143 grams) was added to form a solution. Thereafter,anhydrous aluminum chloride (0.8175 mol, 109 grams) was addedportion-wise over 15 minutes with vigorous gas evolution of hydrochloricacid as determined by odor. The solution turned orange-yellow and thenred. The reaction was stirred for 16 hours under argon, and on removingthe solvent, a solid lump was obtained. The mass was extracted withmethylene chloride (1 liter), which was then dried over potassiumcarbonate and filtered. The filtrate was concentrated using a rotaryevaporator and a vacuum pump to yield an oil which, upon cooling, becamea solid crystalline mass. Recrystallization from methanol (1 liter) at−15° C. gave 82.3 grams of 4′-methylbenzoyl-2,4-dichlorobenzene (meltingpoint 55-56° C.) in the first crop, 32 grams of product (from 500milliliters of methanol) in the second crop, and 16.2 grams of productin the third crop. The total recovered product was 134.7 grams in 65.6%yield.

EXAMPLE XIV

Benzoyl-2,4-dichlorobenzene, of the formula

was prepared as follows. To a 2-liter flask equipped with a mechanicalstirrer, argon inlet, Dean Stark trap, condenser, stopper and situatedin an oil bath was added benzene (200 grams). The oil bath temperaturewas raised to 100° C. and 19 grams of benzene were removed. There was noindication of water. The flask was removed from the oil bath and allowedto cool to 25° C. 2,4-Dichlorobenzoyl chloride (0.683 mol, 143 grams)was added to form a solution. Thereafter, anhydrous aluminum chloride(0.8175 mol, 109 grams) was added portion-wise over 15 minutes withvigorous gas evolution. Large volumes of hydrochloric acid were evolvedas determined by odor. The solution turned orange-yellow and then red.The reaction was stirred for 16 hours under argon and was then added to1 liter of ice water in a 2-liter beaker. The mixture was stirred untilit became white and was then extracted with methylene chloride (1liter). The methylene chloride layer was dried over sodium bicarbonateand filtered. The filtrate was concentrated using a rotary evaporatorand a vacuum pump to yield an oil which, upon cooling, became a solidcrystalline mass (154.8 grams). Recrystallization from methanol gave133.8 grams of benzoyl-2,4-dichlorobenzene as white needles (meltingpoint 41-43° C.) in the first crop.

EXAMPLE XV

2,5-Dichlorobenzoyl chloride was prepared as follows. To a 2-liter,3-neck round-bottom flask situated in an ice bath and equipped with anargon inlet, condenser, and mechanical stirrer was added2,5-dichlorobenzoic acid (93.1 grams) in 400 milliliters ofdichloromethane to form a slurry. Thionyl chloride (85 grams) in 68grams of dichloromethane was then added and the mixture was stirred at25° C. The mixture was then gradually heated and maintained at refluxfor 16 hours. Thionyl chloride was subsequently removed using a Claisendistillation take-off head with heating to greater than 80° C. Thereaction residue was transferred to a 500 milliliter 1-neck round bottomflask and then distilled using a Kugelrohr apparatus and a vacuum pumpat between 70 and 100° C. at 0.1 to 0.3 mm mercury to obtain 82.1 gramsof 2,5-dichlorobenzoyl chloride, trapped with ice bath cooling as ayellow-white solid.

EXAMPLE XVI

Benzoyl-2,5-dichlorobenzene, of the formula

was prepared as follows. To a 2-liter flask equipped with a mechanicalstirrer, argon inlet, Dean Stark trap, condenser, and stopper andsituated in an oil bath was added benzene(140 grams). The oil bathtemperature was raised to 100° C. and 19 grams of benzene were removed.There was no indication of water. The flask was removed from the oilbath and allowed to cool to 25° C. 2,5-Dichlorobenzoyl chloride (92.6grams), prepared as described in Example XV, was added to form asolution. Thereafter, anhydrous aluminum chloride (0.8175 mol, 109grams) was cautiously added portion-wise over 15 minutes with vigorousgas evolution. Large volumes of hydrochloric acid were evolved asdetermined by odor. The solution turned orange-yellow and then red. Thereaction was stirred for 16 hours under argon and was then added to 1liter of ice water in a 2-liter beaker. The mixture was stirred until itbecame white and was then extracted with methylene chloride (1 liter).The methylene chloride layer was dried over sodium bicarbonate andfiltered. The filtrate was concentrated using a rotary evaporator and avacuum pump to yield crystals (103.2 grams). Recrystallization frommethanol gave benzoyl-2,5-dichlorobenzene as white needles (meltingpoint 85-87° C.).

EXAMPLE XVII

4′-Methylbenzoyl-2,5-dichlorobenzene, of the formula

was prepared as follows. To a 2-liter flask equipped with a mechanicalstirrer, argon inlet, Dean Stark trap, condenser, and stopper andsituated in an oil bath was added toluene (200 grams). Thereafter,anhydrous aluminum chloride (64 grams) was cautiously added portion-wiseover 15 minutes with vigorous gas evolution. Large volumes ofhydrochloric acid were evolved as determined by odor. The solutionturned orange-yellow and then red. The reaction was stirred for 16 hoursunder argon and was then added to 1 liter of ice water in a 2-literbeaker. The mixture was stirred until it became white and was thenextracted with methylene chloride (1 liter). The methylene chloridelayer was dried over sodium bicarbonate and filtered. The filtrate wasconcentrated using a rotary evaporator and a vacuum pump to yieldcrystals. Recrystallization from methanol gave 37.6 grams of4′-methylbenzoyl-2,5-dichlorobenzene as light-yellow needles (meltingpoint 107-108° C.).

EXAMPLE XVIII

A polymer of the formula

wherein n represents the number of repeating monomer units was preparedas follows. A 250 milliliter, 3-neck round-bottom flask equipped with aDean-Stark (Barrett) trap, condenser, mechanical stirrer, argon inlet,and stopper was situated in a silicone oil bath.4′-Methylbenzoyl-2,4dichlorobenzene (0.0325 mol, 8.6125 grams, preparedas described in Example XIII), bis-phenol A (Aldrich 23,965-8, 0.035mol, 7.99 grams), potassium carbonate (10.7 grams), anhydrousN,N-dimethylacetamide (60 milliliters), and toluene (60 milliliters,49.1 grams) were added to the flask and heated to 175° C. (oil bathtemperature) while the volatile toluene component was collected andremoved. After 24 hours of heating at 175° C. with continuous stirring,the reaction product was filtered and the filtrate was added to methanolto precipitate the polymer. The wet polymer cake was isolated byfiltration, washed with water, then washed with methanol, and thereaftervacuum dried. The polymer (7.70 grams, 48% yield) was analyzed by gelpermeation chromatography (gpc) (elution solvent was tetrahydrofuran)with the following results: M_(n) 1,898, M_(peak) 2,154, M_(w) 2,470,M_(z) 3,220, and M_(z+1) 4,095.

EXAMPLE XIX

A polymer of the formula

wherein n represents the number of repeating monomer units was preparedby repeating the process of Example XVIII except that the4′-methylbenzoyl-2,4-dichlorobenzene starting material was replaced with8.16 grams (0.0325 mol) of benzoyl-2,4-dichlorobenzene, prepared asdescribed in Example XIV, and the oil bath was heated to 170° C. for 24hours.

EXAMPLE XX

The process of Example I is repeated except that the poly(4-CPK-BPA) isreplaced with the polymer prepared as described in Example XVIII. It isbelieved that similar results will be obtained.

EXAMPLE XXI

The process of Example I is repeated except that the poly(4-CPK-BPA) isreplaced with the polymer prepared as described in Example XIX. It isbelieved that similar results will be obtained.

EXAMPLE XXII

The process of Example III is repeated except that the poly(4-CPK-BPA)is replaced with the polymer prepared as described in Example XVIII. Itis believed that similar results will be obtained.

EXAMPLE XXIII

The process of Example III is repeated except that the poly(4-CPK-BPA)is replaced with the polymer prepared as described in Example XIX. It isbelieved that similar results will be obtained.

Other embodiments and modifications of the present invention may occurto those skilled in the art subsequent to a review of the informationpresented herein; these embodiments and modifications, as well asequivalents thereof, are also included within the scope of thisinvention.

What is claimed is:
 1. A composition which comprises a crosslinked orchain extended polymer of the formula

wherein x is an integer of 0 or 1, A is

or mixtures thereof, B is

wherein v is an integer of from 1 to about 20,

wherein z is an integer of from 2 to about 20,

wherein u is an integer of from 1 to about 20,

wherein w is an integer of from 1 to about 20,

or mixtures thereof, and n is an integer representing the number ofrepeating monomer units, at least some of said crosslinking or chainextension occuring through groups of the formula

wherein R is

wherein R₁, R₂, R₃, and R₄ each, independently of the others, is ahydrogen atom, an alkyl group, a substituted alkyl group, an aryl group,a substituted aryl group, an arylalkyl group, or a substituted arylalkylgroup, and x is 0 or
 1. 2. A composition according to claim 1 wherein Ais

and B is

wherein z is an integer of from 2 to about 20, or a mixture thereof. 3.A composition according to claim 1 wherein the polymer has end groupsderived from the “A” groups of the polymer.
 4. A composition accordingto claim 1 wherein the polymer has end groups derived from the “B”groups of the polymer.
 5. An ink jet printhead which comprises (i) anupper substrate with a set of parallel grooves for subsequent use as inkchannels and a recess for subsequent use as a manifold, the groovesbeing open at one end for serving as droplet emitting nozzles, (ii) alower substrate in which one surface thereof has an array of heatingelements and addressing electrodes formed thereon, and (iii) a layerdeposited on the surface of the lower substrate and over the heatingelements and addressing electrodes and patterned to form recessestherethrough to expose the heating elements and terminal ends of theaddressing electrodes, the upper and lower substrates being aligned,mated, and bonded together to form the printhead with the grooves in theupper substrate being aligned with the heating elements in the lowersubstrate to form droplet emitting nozzles, said layer comprising acrosslinked or chain extended polymer-containing composition accordingto claim
 1. 6. A composition which comprises a crosslinked or chainextended polymer of the formula

wherein x is an integer of 0 or 1, A is

or mixtures thereof, B is

wherein v is an integer of from 1 to about 20,

wherein z is an integer of from 2 to about 20,

wherein u is an integer of from 1 to about 20,

wherein w is an integer of from 1 to about 20,

or mixtures thereof, and n is an integer representing the number ofrepeating monomer units, at least some of said crosslinking or chainextension occuring through groups of the formula

wherein R₁ is an alkyl group or an arylalkyl group, R₂ is an alkyl groupor an arylalkyl group, and R₃ is an alkyl group or a substituted alkylgroup.
 7. A composition according to claim 6 wherein A is

and B is

wherein z is an integer of from 2 to about 20, or a mixture thereof. 8.A composition according to claim 6 wherein the polymer has end groupsderived from the “A” groups of the polymer.
 9. A composition accordingto claim 6 wherein the polymer has end groups derived from the “B”groups of the polymer.
 10. An ink jet printhead which comprises (i) anupper substrate with a set of parallel grooves for subsequent use as inkchannels and a recess for subsequent use as a manifold, the groovesbeing open at one end for serving as droplet emitting nozzles, (ii) alower substrate in which one surface thereof has an array of heatingelements and addressing electrodes formed thereon, and (iii) a layerdeposited on the surface of the lower substrate and over the heatingelements and addressing electrodes and patterned to form recessestherethrough to expose the heating elements and terminal ends of theaddressing electrodes, the upper and lower substrates being aligned,mated, and bonded together to form the printhead with the grooves in theupper substrate being aligned with the heating elements in the lowersubstrate to form droplet emitting nozzles, said layer comprising acrosslinked or chain extended polymer-containing composition accordingto claim
 6. 11. A process which comprises the steps of: (a) reacting ahaloalkylated polymer of the formula

wherein x is an integer of 0 or 1, A is

or mixtures thereof, B is

wherein v is an integer of from 1 to about 20,

wherein z is an integer of from 2 to about 20,

wherein u is an integer of from 1 to about 20,

wherein w is an integer of from 1 to about 20,

or mixtures thereof, and n is an integer representing the number ofrepeating monomer units, with water and a base, thereby forming apolymer with hydroxyalkyl groups; and (b) converting the hydroxyalkylgroups to unsaturated ester groups.
 12. A polymer prepared according tothe process of claim
 11. 13. A process according to claim 11 furthercomprising the step of causing the polymer to become crosslinked orchain extended through the photosensitivity-imparting groups.
 14. Aprocess according to claim 13 wherein crosslinking or chain extension iseffected by heating the polymer to a temperature sufficient to enablethe photosensitivity-imparting groups to form crosslinks or chainextensions in the polymer.
 15. A process according to claim 13 whereincrosslinking or chain extension is effected by exposing the polymer toactinic radiation such that the polymer in exposed areas becomescrosslinked or chain extended.
 16. A process according to claim 15wherein the polymer is exposed in an imagewise pattern such that thepolymer in exposed areas becomes crosslinked or chain extended and thepolymer in unexposed areas does not become crosslinked or chainextended, and wherein subsequent to exposure, the polymer in theunexposed areas is removed from the crosslinked or chain extendedpolymer, thereby forming an image pattern.
 17. A process according toclaim 16 further comprising the steps of: (a) depositing a layercomprising the polymer onto a lower substrate in which one surfacethereof has an array of heating elements and addressing electrodeshaving terminal ends formed thereon, said polymer being deposited ontothe surface having the heating elements and addressing electrodesthereon; (b) exposing the layer to actinic radiation in an imagewisepattern such that the polymer in exposed areas becomes crosslinked orchain extended and the polymer in unexposed areas does not becomecrosslinked or chain extended, wherein the unexposed areas correspond toareas of the lower substrate having thereon the heating elements and theterminal ends of the addressing electrodes; (c) removing the polymer inthe unexposed areas, thereby forming recesses in the layer, saidrecesses exposing the heating elements and the terminal ends of theaddressing electrodes; (d) providing an upper substrate with a set ofparallel grooves for subsequent use as ink channels and a recess forsubsequent use as a manifold, the grooves being open at one end forserving as droplet emitting nozzles; and (e) aligning, mating, andbonding the upper and lower substrates together to form a printhead withthe grooves in the upper substrate being aligned with the heatingelements in the lower substrate to form droplet emitting nozzles,thereby forming a thermal ink jet printhead.
 18. A process according toclaim 11 wherein A is

and B is

wherein z is an integer of from 2 to about 20, or a mixture thereof. 19.A process according to claim 11 wherein the polymer has end groupsderived from the “A” groups of the polymer.
 20. A process according toclaim 11 wherein the polymer has end groups derived from the “B” groupsof the polymer.
 21. A process which comprises the steps of: (a) reactinga polymer of the formula

wherein x is an integer of 0 or 1, A is

or mixtures thereof, B is

wherein v is an integer of from 1 to about 20,

wherein z is an integer of from 2 to about 20,

wherein u is an integer of from 1 to about 20,

wherein w is an integer of from 1 to about 20,

or mixtures thereof, and n is an integer representing the number ofrepeating monomer units, with formaldehyde or paraformaldehyde and abase, thereby forming a photopatternable polymer with hydroxymethylgroups; and (b) converting the hydroxymethyl groups to unsaturated estergroups.
 22. A polymer prepared according to the process of claim
 21. 23.A process according to claim 21 further comprising the step of causingthe polymer to become crosslinked or chain extended through thephotosensitivity-imparting groups.
 24. A process according to claim 23wherein crosslinking or chain extension is effected by heating thepolymer to a temperature sufficient to enable thephotosensitivity-imparting groups to form crosslinks or chain extensionsin the polymer.
 25. A process according to claim 23 wherein crosslinkingor chain extension is effected by exposing the polymer to actinicradiation such that the polymer in exposed areas becomes crosslinked orchain extended.
 26. A process according to claim 25 wherein the polymeris exposed in an imagewise pattern such that the polymer in exposedareas becomes crosslinked or chain extended and the polymer in unexposedareas does not become crosslinked or chain extended, and whereinsubsequent to exposure, the polymer in the unexposed areas is removedfrom the crosslinked or chain extended polymer, thereby forming an imagepattern.
 27. A process according to claim 26 further comprising thesteps of: (a) depositing a layer comprising the polymer onto a lowersubstrate in which one surface thereof has an array of heating elementsand addressing electrodes having terminal ends formed thereon, saidpolymer being deposited onto the surface having the heating elements andaddressing electrodes thereon; (b) exposing the layer to actinicradiation in an imagewise pattern such that the polymer in exposed areasbecomes crosslinked or chain extended and the polymer in unexposed areasdoes not become crosslinked or chain extended, wherein the unexposedareas correspond to areas of the lower substrate having thereon theheating elements and the terminal ends of the addressing electrodes; (c)removing the polymer from the unexposed areas, thereby forming recessesin the layer, said recesses exposing the heating elements and theterminal ends of the addressing electrodes; (d) providing an uppersubstrate with a set of parallel grooves for subsequent use as inkchannels and a recess for subsequent use as a manifold, the groovesbeing open at one end for serving as droplet emitting nozzles; and (e)aligning, mating, and bonding the upper and lower substrates together toform a printhead with the grooves in the upper substrate being alignedwith the heating elements in the lower substrate to form dropletemitting nozzles, thereby forming a thermal ink jet printhead.
 28. Aprocess according to claim 21 wherein A is

and B is

wherein z is an integer of from 2 to about 20, or a mixture thereof. 29.A process according to claim 21 wherein the polymer has end groupsderived from the “A” groups of the polymer.
 30. A process according toclaim 21 wherein the polymer has end groups derived from the “B” groupsof the polymer.